feat(eda): capítulo OUTLIERS — valores atípicos univariantes + multivariantes

Nuevo capítulo dedicado `outliers` para el motor AutomaticEDA que reúne y
profundiza en un solo sitio el análisis de valores atípicos, hoy disperso entre
`num_distr` (conteo por columna) y `modelos` (IsolationForest). Se registra en
`chapters_registry.py` entre `missingness` y `correlacion` (bloque de calidad de
datos: calidad → missingness → outliers).

Contenido del capítulo:
- Resumen univariante por columna: nº y % de atípicos por Tukey (1.5·IQR) y por
  z-score (|z| > 3), con vallas inferior/superior y valores extremos. Ordenado
  por contaminación y marcando las columnas más afectadas. Reusa las funciones
  del registry `build_boxplot_stats` (vallas desde los percentiles del profile)
  y `detect_outliers` (regla z-score sobre la muestra cruda de `ctx`).
- Boxplots de Tukey de las columnas más contaminadas (caja, bigotes y puntos
  atípicos), delegados a la función nueva `build_boxplots_figure`.
- Multivariante: filas anómalas considerando todas las columnas a la vez con
  `isolation_forest_outliers` — nº y % de filas, las más anómalas con su score y
  las dimensiones que las hacen raras (top columnas por |z|, vía la función nueva
  `summarize_outlier_dims`). El detector se corre en vivo sobre `raw_numeric`
  para que el indexado de filas coincida exactamente con el de las dimensiones;
  cae al bloque precomputado del perfil cuando no hay muestra cruda (preset lite).
- Interpretación exploratoria: un atípico no es necesariamente un error
  (distingue error de dato vs dato real extremo) y recomendaciones (revisar,
  winsorizar o re-expresar, enlazando con la re-expresión de Tukey del perfil).

Términos clicables registrados en el glosario compartido: `outlier`,
`tukey_fence`, `zscore`, `isolation_forest`.

Funciones nuevas del registry (dominio datascience, grupo eda):
- `build_boxplots_figure_py_datascience` (figure helper, impura)
- `summarize_outlier_dims_py_datascience` (pura)

El capítulo se activa con ≥1 columna numérica y devuelve None en su ausencia;
lee todo defensivo y nunca lanza. Tests: capítulo (golden + edges + error path +
render PDF/PPTX) y ambas funciones nuevas. Suite de no-regresión de AutomaticEDA
verde. Verificado end-to-end con el dataset Titanic (Fare/Parch/SibSp como las
columnas más contaminadas).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

python/functions/datascience/automatic_eda/chapters/correlacion.py

@@ -31,7 +31,7 @@ import math
 
 from .. import model
 
-CHAPTER_VERSION = "1.0.0"
+CHAPTER_VERSION = "1.1.0"
 CHAPTER_ID = "correlacion"
 CHAPTER_TITLE = "Correlación"
 
@@ -47,6 +47,13 @@ _MAX_MATRIX_LABELS = 16
 # How many pairs to show in each of the top-positive / top-negative tables.
 _TOP_N = 10
 
+# How many of the strongest numeric-numeric pairs to draw as scatter plots on
+# each sign (positive / negative). A scatter per pair carries a fitted line/curve
+# and a relationship-type label; keeping the count small keeps the chapter
+# readable on a phone / a slide. Only signed (Pearson/Spearman) pairs qualify —
+# Cramér's V / correlation ratio pairs are not numeric-numeric, so no scatter.
+_SCATTER_TOP_N = 3
+
 # Glossary terms this chapter explains. Each is registered in the shared
 # collector (ctx['glossary']) and marked clickable on its first appearance in the
 # body — the canonical two-step pattern (see ``cat_distr`` for the reference
@@ -314,6 +321,139 @@ def _fdr_text(corr: dict, mark_term: bool = False) -> str | None:
     return " ".join(parts)
 
 
+def _is_seq(values) -> bool:
+    """True for a non-empty list/tuple of values (a raw numeric column)."""
+    return isinstance(values, (list, tuple)) and len(values) > 0
+
+
+def _select_scatter_pairs(pairs: list, top_n: int = _SCATTER_TOP_N):
+    """Pick the strongest numeric-numeric pairs to draw as scatters.
+
+    Only signed (Pearson/Spearman) pairs are numeric-numeric and thus eligible
+    for a scatter with a fitted curve. Returns up to ``top_n`` of the strongest
+    positive pairs followed by up to ``top_n`` of the strongest negative ones,
+    each ranked by magnitude. Mixed-type metrics (Cramér's V, correlation ratio,
+    mutual information) are excluded — they have no x/y scatter interpretation.
+    """
+    positive = []
+    negative = []
+    for pair in pairs:
+        if not isinstance(pair, dict) or not _is_signed(pair):
+            continue
+        value = pair.get("value")
+        if not _is_num(value):
+            continue
+        if value > 0:
+            positive.append(pair)
+        elif value < 0:
+            negative.append(pair)
+    positive.sort(key=lambda p: abs(float(p.get("value", 0.0))), reverse=True)
+    negative.sort(key=lambda p: abs(float(p.get("value", 0.0))), reverse=True)
+    return positive[:top_n] + negative[:top_n]
+
+
+def _classification_note(a: str, b: str, cls: dict) -> str:
+    """Human-readable sentence describing the relationship of a pair.
+
+    Plain text (not baked into the figure image) so the type label is selectable
+    in the PDF / extractable by pdftotext, and sits right next to its scatter
+    inside the keep-together Group.
+    """
+    tipo = model._safe_str(cls.get("tipo")) or "sin forma clara"
+    bits = []
+    pearson = cls.get("pearson")
+    spearman = cls.get("spearman")
+    r2_lin = cls.get("r2_linear")
+    r2_poly = None
+    for key in ("r2_poly2", "r2_poly3"):
+        v = cls.get(key)
+        if _is_num(v) and (r2_poly is None or float(v) > r2_poly):
+            r2_poly = float(v)
+    if _is_num(pearson):
+        bits.append(f"Pearson r={float(pearson):+.2f}")
+    if _is_num(spearman):
+        bits.append(f"Spearman ρ={float(spearman):+.2f}")
+    if _is_num(r2_lin):
+        bits.append(f"R² lineal={float(r2_lin):.2f}")
+    if r2_poly is not None:
+        bits.append(f"R² polinómico={r2_poly:.2f}")
+    metrics = "; ".join(bits)
+    text = (f"Relación **{tipo}** entre «{a}» y «{b}»."
+            + (f" {metrics}." if metrics else ""))
+    return text
+
+
+def _scatter_blocks(pairs: list, raw_numeric):
+    """Build keep-together scatter Groups for the strongest num-num pairs.
+
+    Returns a list of blocks (a Heading plus one Group per pair), or an empty
+    list when there is no raw numeric data (e.g. the lite profile drops
+    ``ctx['raw_numeric']`` to skip live recomputation) or the relationship
+    helpers are unavailable. Never raises: any failure degrades to no scatters,
+    leaving the matrix + tables intact.
+    """
+    if not isinstance(raw_numeric, dict) or not raw_numeric:
+        return []
+    selected = _select_scatter_pairs(pairs)
+    if not selected:
+        return []
+
+    # The relationship helpers live in the datascience package. Import lazily so
+    # the chapter still builds (matrix + tables) when they are absent.
+    try:
+        from datascience.classify_relationship_type import (
+            classify_relationship_type,
+        )
+        from datascience.relationship_scatter_figure import (
+            relationship_scatter_figure,
+        )
+    except Exception:  # noqa: BLE001 — degrade, never break the chapter.
+        return []
+
+    groups = []
+    for pair in selected:
+        a = pair.get("a")
+        b = pair.get("b")
+        xs = raw_numeric.get(a)
+        ys = raw_numeric.get(b)
+        # Edge: a selected pair has no raw column (aggregated profile, renamed
+        # column, …) — skip just that pair, keep the rest.
+        if not _is_seq(xs) or not _is_seq(ys):
+            continue
+        try:
+            cls = classify_relationship_type(list(xs), list(ys)) or {}
+        except Exception:  # noqa: BLE001
+            continue
+        a_lbl = model._safe_str(a)
+        b_lbl = model._safe_str(b)
+
+        def _make(xs=xs, ys=ys, a_lbl=a_lbl, b_lbl=b_lbl, cls=cls):
+            return relationship_scatter_figure(
+                list(xs), list(ys), x_label=a_lbl, y_label=b_lbl,
+                classification=cls)
+
+        groups.append(model.Group(blocks=[
+            model.Heading(text=f"{a_lbl} ↔ {b_lbl}", level=2),
+            model.Figure(
+                make=_make,
+                caption=(f"Dispersión de «{a_lbl}» frente a «{b_lbl}» con la "
+                         "curva de ajuste del mejor modelo.")),
+            model.Markdown(text=_classification_note(a_lbl, b_lbl, cls)),
+        ]))
+
+    if not groups:
+        return []
+    intro = model.Markdown(text=(
+        "Para los pares numéricos más fuertes (positivos y negativos) se dibuja "
+        "la nube de puntos con su ajuste y se clasifica el **tipo de relación**: "
+        "**lineal** (una recta basta), **polinómica** (curva de grado 2/3 que "
+        "mejora claramente el ajuste lineal), **monótona no-lineal** (crece o "
+        "decrece siempre pero no en línea recta; Spearman ≫ Pearson) o "
+        "**débil/sin forma**."))
+    return [model.Heading(text="Relaciones más fuertes (scatter)", level=2),
+            intro] + groups
+
+
 def build_correlacion(profile: dict, ctx: dict):
     """Build the Correlation Chapter, or None if there are no pairs to show.
 
@@ -392,6 +532,18 @@ def build_correlacion(profile: dict, ctx: dict):
             "No se han hallado correlaciones negativas significativas entre "
             "columnas numéricas.")))
 
+    # 2.5) Scatter plots of the strongest numeric-numeric pairs, each with its
+    # fitted curve and a relationship-type label (lineal / polinómica / monótona
+    # / débil). Needs the raw numeric sample (ctx['raw_numeric'], row-aligned);
+    # when it is absent (aggregated/lite profile) the scatters are simply omitted
+    # and the matrix + tables above stand on their own.
+    raw_numeric = None
+    if isinstance(ctx, dict):
+        raw_numeric = ctx.get("raw_numeric") or profile.get("raw_numeric")
+    else:
+        raw_numeric = profile.get("raw_numeric")
+    blocks.extend(_scatter_blocks(pairs, raw_numeric))
+
     # 3) Spuriousness caveat for level-based correlations (Granger–Newbold).
     caveat = corr.get("levels_caveat")
     if isinstance(caveat, str) and caveat.strip():

python/functions/datascience/automatic_eda/chapters/correlacion_test.py

@@ -175,6 +175,105 @@ def test_anticorte_matriz_ancha_y_etiquetas_largas_no_se_cortan():
         assert "azufre" in _pdf_text(pdf)
 
 
+def _raw_numeric_for_profile(n: int = 80) -> dict:
+    """Row-aligned raw numeric sample matching the signed pairs of _profile().
+
+    Builds columns with a clear, deterministic shape so the relationship-type
+    classifier has something unambiguous to label:
+      - density vs alcohol: strong negative linear (the top-negative pair).
+      - alcohol vs quality: positive linear.
+      - ph, fixed_acidity, sulphates: filler columns for the remaining pairs.
+    """
+    import math as _m
+
+    alcohol = [8.0 + 0.05 * i for i in range(n)]
+    density = [1.0 - 0.002 * a for a in alcohol]           # neg linear vs alcohol
+    quality = [3.0 + 0.4 * a + (0.1 if i % 2 else -0.1)    # pos linear vs alcohol
+               for i, a in enumerate(alcohol)]
+    ph = [3.0 + 0.3 * _m.sin(i / 5.0) for i in range(n)]
+    fixed_acidity = [7.0 - 0.5 * p for p in ph]            # neg linear vs ph
+    sulphates = [0.5 + 0.01 * (i % 7) for i in range(n)]
+    return {
+        "alcohol": alcohol, "density": density, "quality": quality,
+        "ph": ph, "fixed_acidity": fixed_acidity, "sulphates": sulphates,
+    }
+
+
+def test_golden_scatters_de_pares_num_num_con_tipo_de_relacion():
+    """Con ctx['raw_numeric'], el capítulo añade scatters (Figure dentro de Group)
+    de los pares num-num más fuertes, cada uno con su etiqueta de tipo en texto."""
+    from datascience.automatic_eda.model import Group
+
+    ctx = {"raw_numeric": _raw_numeric_for_profile()}
+    ch = build_correlacion(_profile(), ctx)
+    assert ch is not None
+    groups = [b for b in ch.blocks if isinstance(b, Group)]
+    assert groups, "debe emitir al menos un Group con scatter"
+    # Cada Group lleva su figura (lazy) y una nota de texto con el tipo.
+    for g in groups:
+        gkinds = [b.kind for b in g.blocks]
+        assert "figure" in gkinds and "markdown" in gkinds
+    # La sección y la etiqueta de tipo aparecen como texto plano (extraíble).
+    headings = " ".join(b.text for b in ch.blocks if b.kind == "heading")
+    assert "Relaciones más fuertes" in headings
+    body = " ".join(b.text for g in groups for b in g.blocks
+                    if b.kind == "markdown")
+    assert any(t in body for t in
+               ("lineal", "polinómica", "monótona", "sin forma"))
+    # El par num-num más fuerte (density ↔ alcohol) tiene scatter; el par cat-cat
+    # (region ↔ type) NO — no es numérico.
+    assert "density" in body or "alcohol" in body
+    assert "region" not in body and "type" not in body
+
+
+def test_golden_pdf_muestra_scatters_con_etiqueta_de_tipo():
+    """En el PDF, el capítulo Correlación incluye los scatters y su etiqueta de
+    tipo en texto seleccionable (pdftotext la encuentra)."""
+    prof = _profile()
+    ctx = {"raw_numeric": _raw_numeric_for_profile()}
+    with tempfile.TemporaryDirectory() as d:
+        pdf = os.path.join(d, "corr_scatter.pdf")
+        rp = render_automatic_eda_pdf(prof, pdf, {"title": "EDA — wine",
+                                                  "ctx": ctx})
+        assert rp["path"] == pdf and rp["n_pages"] >= 1
+        txt = _pdf_text(pdf)
+        assert "Relaciones" in txt and "scatter" in txt.lower()
+        # Alguna etiqueta de tipo de relación, en texto.
+        assert any(t in txt for t in
+                   ("lineal", "polin", "monóton", "monoton", "sin forma"))
+
+
+def test_edge_sin_raw_numeric_omite_scatters_sin_lanzar():
+    """profile lite / ctx None: sin raw_numeric el capítulo omite los scatters
+    pero sigue emitiendo matriz + tablas (no lanza)."""
+    from datascience.automatic_eda.model import Group
+
+    for ctx in (None, {}, {"raw_numeric": None}, {"raw_numeric": {}}):
+        ch = build_correlacion(_profile(), ctx)
+        assert ch is not None
+        assert not [b for b in ch.blocks if isinstance(b, Group)]
+        # La matriz y al menos una tabla top siguen presentes.
+        assert any(b.kind == "figure" for b in ch.blocks)
+        assert any(b.kind == "data_table" for b in ch.blocks)
+
+
+def test_edge_par_sin_columna_cruda_se_omite_sin_lanzar():
+    """Si un par seleccionado no tiene su columna en raw_numeric, se omite ese
+    par (no lanza); los demás scatters se construyen igual."""
+    from datascience.automatic_eda.model import Group
+
+    raw = _raw_numeric_for_profile()
+    raw.pop("density", None)   # rompe el par density ↔ alcohol
+    ch = build_correlacion(_profile(), {"raw_numeric": raw})
+    assert ch is not None
+    groups = [b for b in ch.blocks if isinstance(b, Group)]
+    body = " ".join(b.text for g in groups for b in g.blocks
+                    if b.kind == "markdown")
+    # density desaparece de los scatters; otros pares (p.ej. ph↔fixed_acidity,
+    # alcohol↔quality) pueden seguir presentes sin error.
+    assert "density" not in body
+
+
 def test_glosario_engancha_metodos_y_fdr():
     """Mejora 4b: los métodos de correlación (Pearson, Spearman, Cramér's V,
     razón de correlación) y la corrección por comparaciones múltiples (FDR) se

python/functions/datascience/automatic_eda/chapters/missingness.py

@@ -0,0 +1,594 @@
+"""Missingness chapter (MISSINGNESS) — patterns of missing data.
+
+Complements the CALIDAD chapter: where CALIDAD reports *how much* is missing per
+column (the null percentage that lowers the completeness score), this chapter
+reports the **pattern** of the missing data — whether columns tend to be missing
+*together* (co-occurrence of absences) or independently. That distinction is what
+separates data that is missing completely at random ([[term:mcar]]MCAR[[/term]])
+from data missing as a function of another variable ([[term:mar]]MAR[[/term]]),
+which is the key question to settle before imputing or modelling.
+
+The chapter activates only when the table actually has missing data (at least one
+column with a null in the aggregated profile); otherwise it returns ``None`` and
+disappears from the document.
+
+Sections, in order:
+
+1. **Resumen global** — % of missing cells in the dataset, number of columns with
+   nulls, and complete rows (no missing) vs incomplete rows (≥1 missing).
+2. **Ranking por columna** — columns sorted by their null percentage, with a
+   horizontal bar figure.
+3. **Co-ocurrencia de ausencias** — the correlation of the binary is-null masks
+   between columns (which columns tend to be missing together): a heatmap plus a
+   table of the top column pairs that co-miss.
+4. **Patrones de fila** — the most frequent "which columns are missing together"
+   row patterns, in the style of missingno's pattern matrix.
+5. **Lectura MCAR/MAR** — an interpretive, *exploratory* note (not a confirmatory
+   test such as Little's) reading the absence correlations as a hint of MCAR
+   (independent absences) vs MAR (co-occurring absences).
+
+The aggregate per-column null counts come from the ``eda`` group ``TableProfile``
+(``columns[i]['null_count'] / 'null_pct'`` and the table-level ``null_cell_pct``).
+The per-row is-null mask needed for co-occurrence is built from raw data: a single
+DuckDB push-down over ``ctx['db_path'] / ctx['table']`` (same pattern as the
+AGREGACION chapter) covering ALL columns, with a fallback to the numeric-only
+``ctx['raw_numeric']`` when no database is reachable. All the heavy lifting is
+delegated to pure registry functions (``missingness_overview``,
+``missingness_correlation``, ``missingness_row_patterns``) and two figure helpers
+(``missingness_rank_bar_figure``, ``missingness_corr_heatmap_figure``); every one
+is imported lazily and degrades to an honest note so this chapter never raises.
+
+Contract: build_<id>(profile, ctx) -> Chapter | None ; CHAPTER_VERSION = "x.y.z".
+"""
+
+from __future__ import annotations
+
+from .. import model
+
+CHAPTER_VERSION = "1.0.0"
+CHAPTER_ID = "missingness"
+CHAPTER_TITLE = "Datos faltantes"
+
+# Sample cap for the per-row is-null mask push-down. Co-occurrence and row
+# patterns are computed on this sample; the global % of missing cells and the
+# per-column ranking come from the (exact) aggregated profile instead.
+MASK_SAMPLE = 5000
+# Thresholds for the MCAR/MAR heuristic note. A pair counts as a *strong*
+# co-occurrence when the absence correlation alone is high; as a *partial*
+# co-occurrence when the absences overlap materially (high Jaccard) even if the
+# Pearson correlation is modest — the usual case when one column is missing far
+# more often than the other (e.g. Cabin 77% vs Age 20% in Titanic), which dilutes
+# the correlation while the rows still co-miss in absolute terms.
+_CORR_STRONG = 0.30
+_JACCARD_NOTABLE = 0.20
+# Rows shown in the top-pairs and row-patterns tables (bounded, never silently
+# truncated: the table note reports the full count).
+_TOP_PAIRS = 12
+_TOP_PATTERNS = 12
+# Truncate long column names in tables (the renderer also wraps).
+_LABEL_MAX = 28
+
+# Glossary terms this chapter explains (contract §11.1). Registered in the shared
+# collector and marked clickable on their first appearance.
+_TERMS = {
+    "missingness": (
+        "Patrón de datos faltantes (missingness)",
+        "El patrón con el que faltan los datos: cuánto falta, en qué columnas y "
+        "si las ausencias de unas columnas coinciden (co-ocurren) con las de "
+        "otras. Analizarlo —no solo contar nulos— distingue datos que faltan al "
+        "azar (MCAR) de los que faltan en función de otra variable (MAR), lo que "
+        "decide cómo imputar o si descartar filas sin sesgar el análisis.",
+    ),
+    "mcar": (
+        "MCAR (Missing Completely At Random)",
+        "Los valores faltan de forma independiente de cualquier dato, observado o "
+        "no: las ausencias de unas columnas no se relacionan entre sí ni con los "
+        "valores. Es el caso más benigno —descartar filas o imputar la media no "
+        "introduce sesgo—, pero rara vez se cumple del todo en datos reales.",
+    ),
+    "mar": (
+        "MAR (Missing At Random)",
+        "La probabilidad de que un valor falte depende de OTRAS variables "
+        "observadas (p. ej. una medición que falta más en cierto grupo). Las "
+        "ausencias co-ocurren entre columnas o se relacionan con los valores de "
+        "otras; imputar exige condicionar en esas variables para no sesgar. La "
+        "co-ocurrencia fuerte de ausencias es un indicio (exploratorio) de MAR.",
+    ),
+}
+
+
+# --------------------------------------------------------------------------- #
+# Small defensive formatters (own copy: the chapter never imports siblings).
+# --------------------------------------------------------------------------- #
+def _fmt_int(value) -> str:
+    if value is None:
+        return "—"
+    try:
+        return f"{int(round(float(value))):,}".replace(",", ".")
+    except (TypeError, ValueError):
+        return model._safe_str(value)
+
+
+def _fmt_pct(value, decimals: int = 1) -> str:
+    """Format an already-0-100 value as a percentage. None -> placeholder."""
+    if value is None:
+        return "—"
+    try:
+        return f"{float(value):.{decimals}f}%"
+    except (TypeError, ValueError):
+        return model._safe_str(value)
+
+
+def _fmt_num(value, decimals: int = 3) -> str:
+    if value is None:
+        return "—"
+    try:
+        f = float(value)
+    except (TypeError, ValueError):
+        return model._safe_str(value)
+    if f != f:  # NaN
+        return "—"
+    text = f"{f:.{decimals}f}".rstrip("0").rstrip(".")
+    return text if text else "0"
+
+
+def _truncate(text, limit: int = _LABEL_MAX) -> str:
+    s = model._safe_str(text)
+    if len(s) <= limit:
+        return s
+    return s[: max(1, limit - 1)].rstrip() + "…"
+
+
+def _term(key: str, label: str, mark: bool) -> str:
+    if mark:
+        return f"[[term:{key}]]**{label}**[[/term]]"
+    return f"**{label}**"
+
+
+# --------------------------------------------------------------------------- #
+# Profile reads (exact, all rows).
+# --------------------------------------------------------------------------- #
+def _null_count_of(col: dict):
+    """Best-effort null count of a column: ``null_count`` or null_pct*n_rows."""
+    nc = col.get("null_count")
+    if isinstance(nc, (int, float)) and not isinstance(nc, bool):
+        return int(nc)
+    np_ = col.get("null_pct")
+    nr = col.get("n_rows")
+    if isinstance(np_, (int, float)) and isinstance(nr, (int, float)):
+        return int(round(float(np_) * float(nr)))
+    return 0
+
+
+def _columns_with_nulls(profile: dict):
+    """Return ``[(name, null_count, null_pct_0_100)]`` for columns with nulls,
+    sorted by null percentage descending. Reads the aggregated profile (exact)."""
+    cols = profile.get("columns") or []
+    out = []
+    for c in cols:
+        if not isinstance(c, dict):
+            continue
+        nc = _null_count_of(c)
+        if nc <= 0:
+            continue
+        np_ = c.get("null_pct")
+        nr = c.get("n_rows") or profile.get("n_rows")
+        if isinstance(np_, (int, float)) and not isinstance(np_, bool):
+            pct = float(np_) * 100.0 if np_ <= 1.0 else float(np_)
+        elif nr:
+            pct = nc / float(nr) * 100.0
+        else:
+            pct = None
+        out.append((c.get("name") or "(col)", nc, pct))
+    out.sort(key=lambda t: (t[2] if t[2] is not None else -1.0), reverse=True)
+    return out
+
+
+def _global_missing_pct(profile: dict):
+    """Table-level % of missing cells (0-100), exact, from the profile."""
+    v = profile.get("null_cell_pct")
+    if isinstance(v, (int, float)) and not isinstance(v, bool):
+        return float(v) * 100.0 if v <= 1.0 else float(v)
+    return None
+
+
+# --------------------------------------------------------------------------- #
+# Per-row is-null mask (sample): DuckDB push-down, fallback to raw_numeric.
+# --------------------------------------------------------------------------- #
+def _build_query_fn(ctx: dict):
+    """Return ``(query_fn, table)`` for a DuckDB-backed ctx, or ``(None, None)``.
+
+    Mirrors build_eda_render_ctx: a read-only closure over the registry wrapper.
+    Only DuckDB is supported here; any other backend degrades to raw_numeric."""
+    db_path = ctx.get("db_path")
+    table = ctx.get("table")
+    if not db_path or not table:
+        return None, None
+    try:
+        from infra import duckdb_query_readonly
+    except Exception:  # noqa: BLE001 — wrapper unavailable -> degrade.
+        return None, None
+
+    def query_fn(sql):
+        return duckdb_query_readonly(db_path, sql)
+
+    return query_fn, table
+
+
+def _null_mask(profile: dict, ctx: dict):
+    """Build the per-row is-null mask ``{col: [0/1, ...]}``.
+
+    Tries a single DuckDB push-down over ALL columns first (so categorical
+    columns like Cabin are covered, not only numeric ones); falls back to the
+    numeric-only ``ctx['raw_numeric']`` (None -> missing); returns ``(None, 0,
+    None)`` when neither is reachable. Never raises.
+    Returns ``(mask, n_sampled, source)`` with source in {"db","raw_numeric"}.
+    """
+    cols = profile.get("columns") or []
+    names = [c.get("name") for c in cols
+             if isinstance(c, dict) and c.get("name")]
+    # 1) DuckDB push-down over every column (covers categoricals too).
+    query_fn, table = _build_query_fn(ctx)
+    if query_fn is not None and names:
+        try:
+            from datascience.extract_null_mask import extract_null_mask
+
+            res = extract_null_mask(query_fn, table, names, max_rows=MASK_SAMPLE)
+            if isinstance(res, dict) and res.get("status") == "ok":
+                mask = res.get("mask") or {}
+                if mask:
+                    return mask, int(res.get("n") or 0), "db"
+        except Exception:  # noqa: BLE001 — degrade to raw_numeric.
+            pass
+    # 2) Fallback: numeric-only mask derived from raw_numeric (None -> missing).
+    rn = ctx.get("raw_numeric")
+    if isinstance(rn, dict) and rn:
+        mask = {}
+        for col, vals in rn.items():
+            if isinstance(vals, (list, tuple)):
+                mask[col] = [1 if v is None else 0 for v in vals]
+        if mask:
+            n = max((len(v) for v in mask.values()), default=0)
+            return mask, n, "raw_numeric"
+    return None, 0, None
+
+
+# --------------------------------------------------------------------------- #
+# Lazy registry delegations (each degrades to None on any failure).
+# --------------------------------------------------------------------------- #
+def _overview(mask: dict):
+    try:
+        from datascience.missingness_overview import missingness_overview
+
+        out = missingness_overview(mask)
+        return out if isinstance(out, dict) else None
+    except Exception:  # noqa: BLE001
+        return None
+
+
+def _correlation(mask: dict, top_k: int):
+    try:
+        from datascience.missingness_correlation import missingness_correlation
+
+        out = missingness_correlation(mask, top_k=top_k)
+        return out if isinstance(out, dict) else None
+    except Exception:  # noqa: BLE001
+        return None
+
+
+def _row_patterns(mask: dict, top_n: int):
+    try:
+        from datascience.missingness_row_patterns import missingness_row_patterns
+
+        out = missingness_row_patterns(mask, top_n=top_n)
+        return out if isinstance(out, dict) else None
+    except Exception:  # noqa: BLE001
+        return None
+
+
+def _rank_bar_make(names, pcts, title):
+    def make():
+        try:
+            from datascience.missingness_rank_bar_figure import (
+                missingness_rank_bar_figure,
+            )
+
+            return missingness_rank_bar_figure(names, pcts, title=title)
+        except Exception:  # noqa: BLE001 — minimal fallback figure.
+            return _fallback_fig("ranking de nulos no disponible")
+
+    return make
+
+
+def _heatmap_make(matrix, labels, title):
+    def make():
+        try:
+            from datascience.missingness_corr_heatmap_figure import (
+                missingness_corr_heatmap_figure,
+            )
+
+            return missingness_corr_heatmap_figure(matrix, labels, title=title)
+        except Exception:  # noqa: BLE001 — minimal fallback figure.
+            return _fallback_fig("heatmap de co-ocurrencia no disponible")
+
+    return make
+
+
+def _fallback_fig(message: str):
+    import matplotlib
+
+    matplotlib.use("Agg")
+    from matplotlib.figure import Figure
+
+    fig = Figure(figsize=(5.0, 2.2))
+    ax = fig.add_subplot(111)
+    ax.text(0.5, 0.5, message, ha="center", va="center")
+    ax.axis("off")
+    return fig
+
+
+# --------------------------------------------------------------------------- #
+# Block builders.
+# --------------------------------------------------------------------------- #
+def _summary_block(profile: dict, with_nulls: list, overview, sampled, n_total):
+    rows = []
+    gpct = _global_missing_pct(profile)
+    rows.append(("Celdas faltantes (global)", _fmt_pct(gpct)))
+    rows.append(("Columnas con faltantes", str(len(with_nulls))))
+    all_null = profile.get("all_null_cols")
+    if isinstance(all_null, (list, tuple)) and all_null:
+        rows.append(("Columnas 100% faltantes", str(len(all_null))))
+    if isinstance(overview, dict):
+        cr = overview.get("complete_rows")
+        ir = overview.get("incomplete_rows")
+        suffix = ""
+        if (isinstance(sampled, int) and isinstance(n_total, (int, float))
+                and sampled and n_total and sampled < n_total):
+            suffix = f" (sobre muestra de {_fmt_int(sampled)} filas)"
+        if cr is not None:
+            rows.append(("Filas completas (sin faltantes)",
+                         f"{_fmt_int(cr)} ({_fmt_pct(overview.get('complete_pct'))})"
+                         + suffix))
+        if ir is not None:
+            rows.append(("Filas con ≥1 faltante",
+                         f"{_fmt_int(ir)} "
+                         f"({_fmt_pct(overview.get('incomplete_pct'))})" + suffix))
+    return model.KVTable(rows=rows, title="Resumen de datos faltantes")
+
+
+def _ranking_block(with_nulls: list):
+    header = ["Columna", "Faltantes", "% faltante"]
+    rows = [[_truncate(n), _fmt_int(c), _fmt_pct(p)] for (n, c, p) in with_nulls]
+    if not rows:
+        return None
+    return model.DataTable(
+        header=header, rows=rows, title="Faltantes por columna",
+        note="ordenado de más a menos faltante")
+
+
+def _ranking_figure(with_nulls: list):
+    names = [n for (n, _, p) in with_nulls if p is not None]
+    pcts = [p for (_, _, p) in with_nulls if p is not None]
+    if not names:
+        return None
+    return model.Figure(
+        make=_rank_bar_make(names, pcts, "% de valores faltantes por columna"),
+        caption="Porcentaje de valores faltantes por columna (barras).")
+
+
+def _pairs_block(corr: dict):
+    """Top column pairs whose absences co-occur, as a table, or None."""
+    pairs = (corr or {}).get("pairs") or []
+    header = ["Columna A", "Columna B", "Corr. ausencia", "Co-faltan", "Jaccard"]
+    rows = []
+    for p in pairs[:_TOP_PAIRS]:
+        if not isinstance(p, dict):
+            continue
+        rows.append([
+            _truncate(p.get("a")),
+            _truncate(p.get("b")),
+            _fmt_num(p.get("corr")),
+            _fmt_int(p.get("co_missing")),
+            _fmt_num(p.get("jaccard")),
+        ])
+    if not rows:
+        return None
+    shown = len(rows)
+    total = len(pairs)
+    note = ("correlación de las máscaras is-null entre columnas; "
+            "«Co-faltan» = nº de filas en que ambas faltan a la vez")
+    if total > shown:
+        note += f" — top {shown} de {total} pares"
+    return model.DataTable(header=header, rows=rows,
+                           title="Pares de columnas que co-faltan", note=note)
+
+
+def _heatmap_block(corr: dict):
+    cols = (corr or {}).get("columns") or []
+    matrix = (corr or {}).get("matrix") or []
+    if len(cols) < 2 or not matrix:
+        return None
+    labels = [_truncate(c, 16) for c in cols]
+    return model.Figure(
+        make=_heatmap_make(matrix, labels, "Co-ocurrencia de ausencias"),
+        caption=("Correlación de las ausencias entre columnas (azul = faltan "
+                 "juntas; rojo = cuando una falta la otra tiende a estar)."))
+
+
+def _patterns_block(patterns_res: dict):
+    patterns = (patterns_res or {}).get("patterns") or []
+    header = ["Columnas que faltan juntas", "Filas", "%"]
+    rows = []
+    for p in patterns[:_TOP_PATTERNS]:
+        if not isinstance(p, dict):
+            continue
+        cols = p.get("missing_cols") or []
+        if cols:
+            label = ", ".join(_truncate(c, 18) for c in cols)
+        else:
+            label = "(fila completa — sin faltantes)"
+        rows.append([label, _fmt_int(p.get("n_rows")), _fmt_pct(p.get("pct"))])
+    if not rows:
+        return None
+    total = (patterns_res or {}).get("n_patterns")
+    shown = len(rows)
+    note = "cada fila es un patrón de «qué columnas faltan juntas»"
+    if isinstance(total, int) and total > shown:
+        note += f" — top {shown} de {total} patrones distintos"
+    return model.DataTable(header=header, rows=rows,
+                           title="Patrones de fila más comunes", note=note)
+
+
+def _mcar_mar_note(corr: dict, mark: bool):
+    """Interpretive, exploratory MCAR/MAR note from the absence correlations.
+
+    Reads the absence correlations at two levels so the verdict never contradicts
+    the visible evidence: a *strong* correlation flags a clear non-random (MAR)
+    pattern; a *partial* overlap (many rows co-miss — high Jaccard — even if the
+    correlation is diluted by one column being missing far more often) flags a
+    localized possible-MAR and cites the concrete co-missing pair; only when
+    neither holds does it read the absences as compatible with MCAR."""
+
+    def _pairs_with(attr_ok):
+        out = []
+        for p in (corr or {}).get("pairs") or []:
+            if isinstance(p, dict) and attr_ok(p):
+                out.append(p)
+        return out
+
+    def _cf(v):
+        try:
+            return float(v)
+        except (TypeError, ValueError):
+            return 0.0
+
+    strong = _pairs_with(lambda p: abs(_cf(p.get("corr"))) >= _CORR_STRONG)
+    partial = _pairs_with(
+        lambda p: _cf(p.get("corr")) > 0 and _cf(p.get("jaccard")) >= _JACCARD_NOTABLE)
+    mcar = _term("mcar", "MCAR", mark)
+    mar = _term("mar", "MAR", mark)
+    head = (
+        "**Lectura exploratoria MCAR/MAR.** Esta es una heurística basada en la "
+        "correlación de las ausencias entre columnas, NO un test confirmatorio "
+        "(como el de Little); orienta, no demuestra. ")
+    if strong:
+        top = strong[0]
+        ev = (f"«{model._safe_str(top.get('a'))}» y "
+              f"«{model._safe_str(top.get('b'))}» "
+              f"(corr {_fmt_num(top.get('corr'))})")
+        body = (
+            f"Hay ausencias que co-ocurren con fuerza —{ev}—: las columnas no "
+            f"faltan de forma independiente, lo que es un indicio de un patrón no "
+            f"aleatorio ({mar}). Antes de imputar o descartar filas conviene "
+            f"comprobar si la ausencia depende de otra variable observada; en ese "
+            f"caso la imputación debería condicionar en ella para no sesgar.")
+    elif partial:
+        top = max(partial, key=lambda p: _cf(p.get("jaccard")))
+        ev = (f"«{model._safe_str(top.get('a'))}» y "
+              f"«{model._safe_str(top.get('b'))}» faltan a la vez en "
+              f"{_fmt_int(top.get('co_missing'))} filas "
+              f"(Jaccard {_fmt_num(top.get('jaccard'))})")
+        body = (
+            f"Hay co-ocurrencia parcial de ausencias —{ev}—: algunas columnas "
+            f"tienden a faltar juntas aunque la correlación global sea modesta "
+            f"(habitual cuando una columna falta mucho más que la otra). Es un "
+            f"indicio de un posible patrón localizado no aleatorio ({mar}); "
+            f"conviene revisar si esa ausencia depende de otra variable observada "
+            f"antes de imputar, en lugar de asumir que faltan al azar.")
+    else:
+        body = (
+            f"Las ausencias entre columnas no muestran correlación ni solape "
+            f"relevante: parecen independientes, lo que es compatible con que "
+            f"falten al azar ({mcar}). Aun así, la ausencia podría depender de "
+            f"variables no observadas (la heurística no lo descarta).")
+    return model.Markdown(text=head + body)
+
+
+def _intro_block(mark: bool, source):
+    missingness = _term("missingness", "missingness", mark)
+    text = (
+        f"Este capítulo analiza el {missingness} de la tabla: no solo cuánto "
+        "falta (eso lo cubre la calidad), sino DÓNDE falta y si las columnas "
+        "faltan juntas. La co-ocurrencia de ausencias se calcula sobre la matriz "
+        "binaria «is-null» por fila.")
+    if source == "raw_numeric":
+        text += (" Nota: no se pudo leer la tabla cruda completa, así que la "
+                 "co-ocurrencia se limita a las columnas numéricas disponibles.")
+    return model.Markdown(text=text)
+
+
+# --------------------------------------------------------------------------- #
+# Entry point.
+# --------------------------------------------------------------------------- #
+def build_missingness(profile: dict, ctx: dict):
+    """Build the missingness Chapter, or None if the table has no missing data."""
+    if not isinstance(profile, dict):
+        profile = {}
+    ctx = ctx or {}
+
+    with_nulls = _columns_with_nulls(profile)
+    if not with_nulls:
+        return None  # no missing data anywhere -> chapter does not apply.
+
+    # Register glossary terms (if a collector is present) and mark them clickable.
+    glossary = ctx.get("glossary")
+    mark = False
+    if isinstance(glossary, model.GlossaryCollector):
+        for key, (label, definition) in _TERMS.items():
+            glossary.add(key, label, definition)
+        mark = True
+
+    # Per-row is-null mask (sample) for co-occurrence and row patterns.
+    mask, sampled, source = _null_mask(profile, ctx)
+    overview = _overview(mask) if mask else None
+    n_total = profile.get("n_rows")
+
+    blocks = [
+        model.Heading(text="Cuánto y dónde faltan datos", level=2),
+        _intro_block(mark, source),
+        _summary_block(profile, with_nulls, overview, sampled, n_total),
+        model.Heading(text="Faltantes por columna", level=2),
+    ]
+    ranking = _ranking_block(with_nulls)
+    if ranking is not None:
+        blocks.append(ranking)
+    rank_fig = _ranking_figure(with_nulls)
+    if rank_fig is not None:
+        blocks.append(rank_fig)
+
+    # Co-occurrence + row patterns need the per-row mask. Without it, say so.
+    if not mask:
+        blocks.append(model.Note(
+            "No se pudo construir la matriz «is-null» por fila (sin acceso a los "
+            "datos crudos), así que no se analiza la co-ocurrencia de ausencias "
+            "ni los patrones de fila en este informe."))
+        return model.Chapter(id=CHAPTER_ID, title=CHAPTER_TITLE,
+                             version=CHAPTER_VERSION, blocks=blocks)
+
+    corr = _correlation(mask, _TOP_PAIRS) or {}
+    co_blocks = [model.Heading(text="Co-ocurrencia de ausencias", level=2)]
+    heatmap = _heatmap_block(corr)
+    if heatmap is not None:
+        co_blocks.append(heatmap)
+    pairs = _pairs_block(corr)
+    if pairs is not None:
+        co_blocks.append(pairs)
+    if heatmap is None and pairs is None:
+        co_blocks.append(model.Note(
+            "Ninguna pareja de columnas comparte ausencias con variación "
+            "suficiente para correlacionarlas (p. ej. una sola columna con "
+            "faltantes), así que no hay co-ocurrencia que mostrar."))
+    # Keep the co-occurrence heading next to its heatmap and table.
+    blocks.append(model.Group(blocks=co_blocks))
+
+    patterns_res = _row_patterns(mask, _TOP_PATTERNS) or {}
+    patterns = _patterns_block(patterns_res)
+    if patterns is not None:
+        blocks.append(model.Heading(text="Patrones de fila", level=2))
+        blocks.append(patterns)
+
+    blocks.append(model.Heading(text="Lectura MCAR / MAR", level=2))
+    blocks.append(_mcar_mar_note(corr, mark))
+
+    return model.Chapter(id=CHAPTER_ID, title=CHAPTER_TITLE,
+                         version=CHAPTER_VERSION, blocks=blocks)

python/functions/datascience/automatic_eda/chapters/missingness_test.py

@@ -0,0 +1,162 @@
+"""Tests for the MISSINGNESS chapter.
+
+Covers the Definition of Done for this chapter:
+  * Activates (non-None Chapter with the expected sections) when the profile has
+    missing data, building the co-occurrence from the per-row is-null mask.
+  * Returns None when the table has no missing data at all (edge case).
+  * Registers the MCAR/MAR/missingness glossary terms.
+  * The DuckDB push-down path covers categorical columns (not only numeric),
+    so a categorical column that co-misses with a numeric one is detected.
+"""
+
+import os
+import sys
+
+_HERE = os.path.dirname(os.path.abspath(__file__))
+_FUNCTIONS = os.path.abspath(os.path.join(_HERE, "..", "..", ".."))  # python/functions
+if _FUNCTIONS not in sys.path:
+    sys.path.insert(0, _FUNCTIONS)
+
+from datascience.automatic_eda import model  # noqa: E402
+from datascience.automatic_eda.chapters.missingness import (  # noqa: E402
+    build_missingness,
+)
+
+
+def _titles(chapter):
+    """Collect heading texts and table/figure titles for assertions."""
+    out = []
+    for b in chapter.blocks:
+        kind = getattr(b, "kind", None)
+        if kind == "heading":
+            out.append(("heading", getattr(b, "text", "")))
+        elif kind in ("data_table", "kv_table"):
+            out.append((kind, getattr(b, "title", "")))
+        elif kind == "group":
+            for inner in getattr(b, "blocks", []):
+                ik = getattr(inner, "kind", None)
+                if ik == "heading":
+                    out.append(("heading", getattr(inner, "text", "")))
+                elif ik in ("data_table", "kv_table"):
+                    out.append((ik, getattr(inner, "title", "")))
+                elif ik == "figure":
+                    out.append(("figure", getattr(inner, "caption", "")))
+        elif kind == "figure":
+            out.append(("figure", getattr(b, "caption", "")))
+    return out
+
+
+def _all_text(chapter):
+    parts = []
+    def walk(blocks):
+        for b in blocks:
+            for attr in ("text", "title", "note", "caption"):
+                v = getattr(b, attr, None)
+                if v:
+                    parts.append(str(v))
+            if getattr(b, "kind", None) == "group":
+                walk(getattr(b, "blocks", []))
+    walk(chapter.blocks)
+    return "\n".join(parts)
+
+
+def test_returns_none_when_no_missing_data():
+    profile = {
+        "n_rows": 4,
+        "null_cell_pct": 0.0,
+        "columns": [
+            {"name": "a", "null_count": 0, "null_pct": 0.0, "n_rows": 4},
+            {"name": "b", "null_count": 0, "null_pct": 0.0, "n_rows": 4},
+        ],
+    }
+    assert build_missingness(profile, {}) is None
+
+
+def test_activates_with_cooccurrence_via_raw_numeric():
+    # a and b are missing in EXACTLY the same rows (0,1,2) -> perfect absence
+    # correlation. c has no nulls. No db_path -> the chapter falls back to the
+    # numeric raw_numeric mask.
+    profile = {
+        "n_rows": 6,
+        "null_cell_pct": (0.5 + 0.5 + 0.0) / 3.0,
+        "columns": [
+            {"name": "a", "null_count": 3, "null_pct": 0.5, "n_rows": 6},
+            {"name": "b", "null_count": 3, "null_pct": 0.5, "n_rows": 6},
+            {"name": "c", "null_count": 0, "null_pct": 0.0, "n_rows": 6},
+        ],
+    }
+    glossary = model.GlossaryCollector()
+    ctx = {
+        "raw_numeric": {
+            "a": [None, None, None, 1.0, 2.0, 3.0],
+            "b": [None, None, None, 4.0, 5.0, 6.0],
+        },
+        "glossary": glossary,
+    }
+    ch = build_missingness(profile, ctx)
+    assert ch is not None
+    assert ch.id == "missingness"
+    assert ch.blocks
+
+    titles = _titles(ch)
+    headings = {t for (k, t) in titles if k == "heading"}
+    # Core sections present.
+    assert any("Cuánto y dónde" in h for h in headings)
+    assert any("Faltantes por columna" in h for h in headings)
+    assert any("Co-ocurrencia" in h for h in headings)
+    assert any("MCAR" in h for h in headings)
+    # A summary KVTable, a ranking DataTable, a co-occurrence figure and the
+    # pairs table all exist.
+    kinds = {k for (k, _) in titles}
+    assert "kv_table" in kinds
+    assert "data_table" in kinds
+    assert "figure" in kinds
+
+    # Glossary terms registered.
+    keys = {t["key"] for t in glossary.terms()}
+    assert {"missingness", "mcar", "mar"} <= keys
+
+    # The MCAR/MAR note reads the co-occurrence; with a perfect overlap it must
+    # flag the non-random (MAR) reading.
+    text = _all_text(ch)
+    assert "MAR" in text
+
+
+def test_db_pushdown_covers_categorical_column(tmp_path):
+    """The is-null mask push-down must cover a categorical column, so a
+    categorical that co-misses with a numeric one shows up in the pairs."""
+    import duckdb
+
+    db = str(tmp_path / "miss.duckdb")
+    con = duckdb.connect(db)
+    con.execute("CREATE TABLE t (num1 DOUBLE, num2 DOUBLE, cat VARCHAR)")
+    # num1 and cat are NULL together in the first 4 of 10 rows; num2 never null.
+    rows = []
+    for i in range(10):
+        if i < 4:
+            rows.append((None, float(i), None))
+        else:
+            rows.append((float(i), float(i), f"c{i}"))
+    con.executemany("INSERT INTO t VALUES (?,?,?)", rows)
+    con.close()
+
+    profile = {
+        "n_rows": 10,
+        "null_cell_pct": (0.4 + 0.0 + 0.4) / 3.0,
+        "columns": [
+            {"name": "num1", "null_count": 4, "null_pct": 0.4, "n_rows": 10},
+            {"name": "num2", "null_count": 0, "null_pct": 0.0, "n_rows": 10},
+            {"name": "cat", "null_count": 4, "null_pct": 0.4, "n_rows": 10},
+        ],
+    }
+    ctx = {"db_path": db, "table": "t", "glossary": model.GlossaryCollector()}
+    ch = build_missingness(profile, ctx)
+    assert ch is not None
+
+    # The pairs table must mention both num1 and cat (they co-miss perfectly),
+    # which is only possible if the mask covered the categorical column.
+    text = _all_text(ch)
+    assert "num1" in text and "cat" in text
+    # Co-occurrence section + a pairs data table exist.
+    titles = _titles(ch)
+    assert any("co-faltan" in (t or "").lower() for (k, t) in titles)

python/functions/datascience/automatic_eda/chapters/outliers.py

@@ -0,0 +1,593 @@
+"""Outliers chapter (OUTLIERS) — univariate + multivariate atypical values.
+
+Today the analysis of atypical values is scattered across the document: the
+NUM DISTR chapter mentions the per-column outlier count inside each distribution
+figure, and the MODELOS chapter runs Isolation Forest as one of several cheap
+models. This chapter gathers and deepens the whole outlier story in a single
+place, with its interpretation: an [[term:outlier]]outlier[[/term]] is **not
+necessarily an error** — it can be a legitimate, extreme but real observation —
+so the reading is exploratory (what to look at), never confirmatory (what to
+delete).
+
+Sections, in order:
+
+1. **Resumen univariante por columna** — for every numeric column, the number
+   and percentage of atypical values by two complementary criteria: Tukey's
+   1.5·IQR rule ([[term:tukey_fence]]vallas de Tukey[[/term]]) and the
+   [[term:zscore]]z-score[[/term]] rule (|z| > 3). The most contaminated columns
+   are flagged. The fences come from the pure registry function
+   ``build_boxplot_stats`` (derived from the profile percentiles); the per-column
+   counts use the raw sample in ``ctx['raw_numeric']`` when available (the exact
+   count), degrading to the profile's own z-score counts otherwise.
+2. **Boxplots** — a single figure with the Tukey boxplots of the most
+   contaminated columns (box, whiskers and atypical points), delegated to the
+   reusable registry helper ``build_boxplots_figure``.
+3. **Multivariante (filas anómalas)** — rows that are atypical considering ALL
+   columns at once, via the registry function ``isolation_forest_outliers``: the
+   count and percentage of anomalous rows, the most anomalous rows with their
+   score, and the dimensions that make each one rare (top columns by |z|, via
+   ``summarize_outlier_dims``). Run live on ``ctx['raw_numeric']`` (the same
+   numeric columns ``summarize_outlier_dims`` uses, so the row indexing stays
+   coherent and the dimension breakdown is correct); falls back to the
+   precomputed ``profile['models']['outliers']`` only when no raw sample is
+   available (e.g. the lite preset), where no per-row breakdown is shown.
+4. **Interpretación** — outlier ≠ error: how to tell a data-entry error from a
+   genuine extreme value, and what to do (inspect, winsorize, or re-express —
+   linking to the Tukey re-expression the profile already computes).
+
+The chapter activates whenever the table has at least one numeric column; with
+no numeric column it returns ``None`` and disappears from the document.
+
+Reads everything defensively (``.get``) and never raises: every registry
+delegation is imported lazily and degraded to an honest note on any failure.
+
+Contract: build_<id>(profile, ctx) -> Chapter | None ; CHAPTER_VERSION = "x.y.z".
+"""
+
+from __future__ import annotations
+
+from .. import model
+
+CHAPTER_VERSION = "1.0.0"
+CHAPTER_ID = "outliers"
+CHAPTER_TITLE = "Valores atípicos"
+
+# z-score threshold for the univariate z rule: |z| > 3 flags a value ~3 standard
+# deviations from the mean (≈99.7% of a normal distribution lies within ±3σ).
+_Z_THRESH = 3.0
+# How many columns to draw in the boxplots figure (most contaminated first) and
+# how many anomalous rows to list in the multivariate table.
+_TOP_BOX = 12
+_TOP_ROWS = 12
+# Cap on the raw atypical values passed as boxplot fliers, so a heavy-tailed
+# column does not flood the figure with thousands of points.
+_MAX_FLIERS = 200
+# How many columns flagged as "most contaminated" in the summary note.
+_TOP_FLAGGED = 3
+
+# Glossary terms this chapter explains (contract §11.1). Registered in the shared
+# collector and marked clickable on first appearance. ``isolation_forest`` and
+# ``zscore`` may also be registered by the MODELOS chapter — ``add`` is
+# idempotent (first definition wins), so registering them here is harmless and
+# keeps this chapter self-contained when MODELOS does not render.
+_TERM_DEFS = {
+    "outlier": (
+        "Valor atípico (outlier)",
+        "Una observación que se aparta mucho del grueso de los datos. Un atípico "
+        "NO es necesariamente un error: puede ser un fallo de medida o de "
+        "registro, pero también un dato real extremo (un cliente que gasta diez "
+        "veces la media, un día de ventas excepcional). Por eso se señalan para "
+        "revisarlos, no para borrarlos automáticamente.",
+    ),
+    "tukey_fence": (
+        "Vallas de Tukey (1,5·IQR)",
+        "Regla clásica para marcar atípicos a partir de los cuartiles: se calcula "
+        "el rango intercuartílico IQR = P75 − P25 y se trazan dos vallas, una "
+        "inferior en P25 − 1,5·IQR y otra superior en P75 + 1,5·IQR. Los valores "
+        "que caen fuera de esas vallas se consideran atípicos. Es robusta porque "
+        "se apoya en la mediana y los cuartiles, no en la media.",
+    ),
+    "zscore": (
+        "z-score (puntuación típica)",
+        "Mide a cuántas desviaciones típicas está un valor de la media de su "
+        "columna: z = (valor − media) / desviación típica. Un |z| grande (aquí > "
+        "3) señala un valor alejado del centro. A diferencia de las vallas de "
+        "Tukey, el z-score usa media y desviación, así que es más sensible a la "
+        "presencia de los propios atípicos.",
+    ),
+    "isolation_forest": (
+        "Isolation Forest (anomalías multivariantes)",
+        "Algoritmo de detección de anomalías que considera TODAS las columnas a "
+        "la vez: construye árboles que parten el espacio con cortes aleatorios y "
+        "mide cuántos cortes hacen falta para aislar cada fila. Las filas raras "
+        "se aíslan con muy pocos cortes y se marcan como atípicas según un umbral "
+        "de contaminación. Detecta combinaciones de valores poco frecuentes que "
+        "ninguna columna por separado revelaría.",
+    ),
+}
+
+
+# --------------------------------------------------------------------------- #
+# Lazy registry delegations (each degrades to None / no-op on any failure).
+# --------------------------------------------------------------------------- #
+def _load_build_boxplot_stats():
+    try:
+        from datascience.build_boxplot_stats import build_boxplot_stats
+        return build_boxplot_stats
+    except Exception:  # noqa: BLE001
+        return None
+
+
+def _load_detect_outliers():
+    # detect_outliers lives in the monolithic ``datascience.datascience`` module
+    # (file_path datascience.py), not in its own submodule — try both shapes.
+    try:
+        from datascience.datascience import detect_outliers
+        return detect_outliers
+    except Exception:  # noqa: BLE001
+        try:
+            from datascience import detect_outliers
+            return detect_outliers
+        except Exception:  # noqa: BLE001
+            return None
+
+
+def _load_isolation_forest():
+    try:
+        from datascience.isolation_forest_outliers import isolation_forest_outliers
+        return isolation_forest_outliers
+    except Exception:  # noqa: BLE001
+        return None
+
+
+def _load_summarize_dims():
+    try:
+        from datascience.summarize_outlier_dims import summarize_outlier_dims
+        return summarize_outlier_dims
+    except Exception:  # noqa: BLE001
+        return None
+
+
+# --------------------------------------------------------------------------- #
+# Defensive formatters (own copy: the chapter never imports siblings).
+# --------------------------------------------------------------------------- #
+def _fmt_num(value, decimals: int = 3) -> str:
+    if value is None:
+        return "—"
+    if isinstance(value, bool):
+        return "sí" if value else "no"
+    if isinstance(value, int):
+        return f"{value:,}".replace(",", ".")
+    if isinstance(value, float):
+        if value != value:  # NaN
+            return "—"
+        if value in (float("inf"), float("-inf")):
+            return str(value)
+        text = f"{value:.{decimals}f}".rstrip("0").rstrip(".")
+        return text if text else "0"
+    return model._safe_str(value)
+
+
+def _fmt_int(value) -> str:
+    if value is None:
+        return "—"
+    try:
+        return f"{int(round(float(value))):,}".replace(",", ".")
+    except (TypeError, ValueError):
+        return model._safe_str(value)
+
+
+def _fmt_pct(value, decimals: int = 2) -> str:
+    """Format an already-0-100 value as a percentage. None -> placeholder."""
+    if value is None:
+        return "—"
+    try:
+        return f"{float(value):.{decimals}f}%"
+    except (TypeError, ValueError):
+        return model._safe_str(value)
+
+
+def _term(mark: bool, key: str, text: str) -> str:
+    return f"[[term:{key}]]{text}[[/term]]" if mark else text
+
+
+def _is_dict(v) -> bool:
+    return isinstance(v, dict)
+
+
+# --------------------------------------------------------------------------- #
+# Profile reads.
+# --------------------------------------------------------------------------- #
+def _numeric_columns(profile: dict) -> list:
+    """Return [(name, numeric_dict)] for numeric columns with usable stats."""
+    out = []
+    for col in profile.get("columns") or []:
+        if not isinstance(col, dict):
+            continue
+        if col.get("inferred_type") != "numeric":
+            continue
+        num = col.get("numeric")
+        if not isinstance(num, dict) or not num:
+            continue
+        if num.get("mean") is None and num.get("median") is None:
+            continue
+        out.append((col.get("name") or "(columna)", num))
+    return out
+
+
+def _clean_values(raw):
+    """Return the finite float values of a raw column list (drop None/NaN/inf)."""
+    if not isinstance(raw, (list, tuple)):
+        return None
+    vals = []
+    for v in raw:
+        if v is None or isinstance(v, bool):
+            continue
+        try:
+            f = float(v)
+        except (TypeError, ValueError):
+            continue
+        if f != f or f in (float("inf"), float("-inf")):
+            continue
+        vals.append(f)
+    return vals
+
+
+# --------------------------------------------------------------------------- #
+# Per-column univariate summary.
+# --------------------------------------------------------------------------- #
+def _univariate_row(name, numeric, raw_vals, box_fn, detect_fn):
+    """Compute one univariate summary row + boxplot inputs for a column.
+
+    Returns a dict with the table cells and, when raw values are available, the
+    exact Tukey/z counts and the list of atypical (flier) values; otherwise it
+    degrades to the profile's own z-score counts and the fence flags.
+    """
+    box = {}
+    if box_fn is not None:
+        try:
+            box = box_fn(numeric) or {}
+        except Exception:  # noqa: BLE001
+            box = {}
+    lf = box.get("lower_fence")
+    uf = box.get("upper_fence")
+
+    vals = _clean_values(raw_vals)
+    n_tukey = pct_tukey = None
+    n_z = pct_z = None
+    low_extreme = high_extreme = None
+    fliers = []
+    contamination = None  # metric used to rank columns (prefer Tukey %).
+
+    if vals:
+        n = len(vals)
+        tukey_out = []
+        for v in vals:
+            below = (lf is not None and v < lf)
+            above = (uf is not None and v > uf)
+            if below or above:
+                tukey_out.append(v)
+        n_tukey = len(tukey_out)
+        pct_tukey = 100.0 * n_tukey / n if n else None
+        if tukey_out:
+            low_extreme = min(tukey_out)
+            high_extreme = max(tukey_out)
+            fliers = tukey_out[:_MAX_FLIERS]
+        # z-score rule via the registry function (returns parallel bools).
+        if detect_fn is not None:
+            try:
+                flags = detect_fn(vals, _Z_THRESH) or []
+                n_z = int(sum(1 for b in flags if b))
+                pct_z = 100.0 * n_z / n if n else None
+            except Exception:  # noqa: BLE001
+                n_z = pct_z = None
+        contamination = pct_tukey
+    else:
+        # Degrade: no raw sample for this column. The profile's own outlier
+        # count/pct come from the z-score block (build_boxplot_stats note); the
+        # Tukey count is unknown, only the fence flags are.
+        n_z = numeric.get("n_outliers")
+        pct_z = numeric.get("outlier_pct")
+        if box.get("has_low_outliers") and box.get("min") is not None:
+            low_extreme = box.get("min")
+        if box.get("has_high_outliers") and box.get("max") is not None:
+            high_extreme = box.get("max")
+        contamination = pct_z if isinstance(pct_z, (int, float)) else None
+
+    # Compact "extremos atípicos" cell: down/up arrows for the low/high tail.
+    extremes = []
+    if low_extreme is not None:
+        extremes.append(f"↓ {_fmt_num(low_extreme)}")
+    if high_extreme is not None:
+        extremes.append(f"↑ {_fmt_num(high_extreme)}")
+    extremes_cell = "  ".join(extremes) if extremes else "—"
+
+    return {
+        "name": model._safe_str(name),
+        "n_tukey": n_tukey,
+        "pct_tukey": pct_tukey,
+        "n_z": n_z,
+        "pct_z": pct_z,
+        "lower_fence": lf,
+        "upper_fence": uf,
+        "extremes": extremes_cell,
+        "box": box,
+        "fliers": fliers,
+        "has_raw": bool(vals),
+        "contamination": contamination if isinstance(contamination, (int, float)) else -1.0,
+    }
+
+
+def _univariate_table(rows: list) -> model.DataTable:
+    header = ["Columna", "Atípicos Tukey", "% Tukey", "Atípicos z", "% z",
+              "Valla inf.", "Valla sup.", "Extremos atípicos"]
+    table_rows = []
+    for r in rows:
+        table_rows.append([
+            r["name"],
+            _fmt_int(r["n_tukey"]) if r["n_tukey"] is not None else "—",
+            _fmt_pct(r["pct_tukey"]) if r["pct_tukey"] is not None else "—",
+            _fmt_int(r["n_z"]) if r["n_z"] is not None else "—",
+            _fmt_pct(r["pct_z"]) if r["pct_z"] is not None else "—",
+            _fmt_num(r["lower_fence"]),
+            _fmt_num(r["upper_fence"]),
+            r["extremes"],
+        ])
+    return model.DataTable(
+        header=header, rows=table_rows,
+        title="Valores atípicos por columna",
+        note="Tukey = fuera de las vallas 1,5·IQR · z = |z-score| > 3 · "
+             "ordenado de más a menos contaminada")
+
+
+# --------------------------------------------------------------------------- #
+# Multivariate (Isolation Forest) section.
+# --------------------------------------------------------------------------- #
+def _resolve_multivariate(profile: dict, ctx: dict, raw_numeric):
+    """Return (outliers_dict_or_None, source).
+
+    Prefers a LIVE Isolation Forest over ``raw_numeric`` so the detector and
+    ``summarize_outlier_dims`` use EXACTLY the same numeric columns and the same
+    valid-row indexing — otherwise the precomputed ``profile['models']
+    ['outliers']`` (run by MODELOS over a possibly different column subset) would
+    yield ``row_index`` values that no longer point at the rows
+    ``summarize_outlier_dims`` reconstructs, mislabelling the "dimensions that
+    make each row rare". Falls back to the precomputed block when no raw sample
+    is available (e.g. the lite preset drops ``raw_numeric``)."""
+    if _is_dict(raw_numeric) and raw_numeric:
+        iso = _load_isolation_forest()
+        if iso is not None:
+            try:
+                out = iso(raw_numeric)
+                if _is_dict(out) and out.get("n_outliers") is not None and out.get("n_rows_used"):
+                    return out, "live"
+            except Exception:  # noqa: BLE001
+                pass
+    # Fallback: the model the MODELOS chapter already computed (no raw sample to
+    # recompute against, so no per-row dimension breakdown either).
+    models = profile.get("models") if _is_dict(profile.get("models")) else {}
+    pre = models.get("outliers") if _is_dict(models) else None
+    if _is_dict(pre) and pre.get("n_outliers") is not None and pre.get("n_rows_used"):
+        return pre, "precomputed"
+    return None, "none"
+
+
+def _multivariate_blocks(outliers: dict, raw_numeric, mark: bool) -> list:
+    isof = _term(mark, "isolation_forest", "**Isolation Forest**")
+    blocks = [
+        model.Heading(text="Filas atípicas (multivariante)", level=2),
+        model.Markdown(text=(
+            f"Hasta aquí cada columna se ha mirado por separado. {isof} busca "
+            "filas raras considerando **todas las columnas a la vez**: una fila "
+            "puede ser normal en cada variable y aun así ser atípica por la "
+            "**combinación** de sus valores (p. ej. una edad baja con una tarifa "
+            "muy alta). La tabla resume cuántas filas se marcaron y el umbral de "
+            "decisión.")),
+        model.KVTable(rows=[
+            ("Filas analizadas", _fmt_int(outliers.get("n_rows_used"))),
+            ("Columnas consideradas", _fmt_int(outliers.get("n_features"))),
+            ("Filas atípicas", _fmt_int(outliers.get("n_outliers"))),
+            ("% filas atípicas", _fmt_pct(outliers.get("outlier_pct"))),
+            ("Umbral de decisión", _fmt_num(outliers.get("threshold"), 4)),
+        ], title="Anomalías multivariantes"),
+    ]
+
+    rows_in = outliers.get("outlier_rows") or []
+    if not rows_in:
+        return blocks
+
+    # Enrich each anomalous row with the dimensions that make it rare, when the
+    # raw sample is available (summarize_outlier_dims reconstructs the same
+    # valid-row indexing as isolation_forest_outliers).
+    dims_by_row = {}
+    if _is_dict(raw_numeric) and raw_numeric:
+        summ = _load_summarize_dims()
+        if summ is not None:
+            try:
+                enriched = summ(raw_numeric, rows_in, top_k=3) or []
+                for e in enriched:
+                    if _is_dict(e) and e.get("row_index") is not None:
+                        dims_by_row[e.get("row_index")] = e.get("dims") or []
+            except Exception:  # noqa: BLE001
+                dims_by_row = {}
+
+    has_dims = bool(dims_by_row)
+    header = ["Fila (entre válidas)", "Score"]
+    if has_dims:
+        header.append("Dimensiones que la hacen rara (col = valor, z)")
+    table_rows = []
+    for r in rows_in[:_TOP_ROWS]:
+        if not _is_dict(r):
+            continue
+        ridx = r.get("row_index")
+        cells = [_fmt_int(ridx), _fmt_num(r.get("score"), 4)]
+        if has_dims:
+            dims = dims_by_row.get(ridx) or []
+            parts = []
+            for d in dims:
+                if not _is_dict(d):
+                    continue
+                parts.append(
+                    f"{model._safe_str(d.get('col'))} = {_fmt_num(d.get('value'))} "
+                    f"(z {_fmt_num(d.get('z'), 2)})")
+            cells.append("; ".join(parts) if parts else "—")
+        table_rows.append(cells)
+
+    if table_rows:
+        shown = len(table_rows)
+        total = outliers.get("n_outliers")
+        note = "las filas más anómalas primero (score más bajo = más rara)"
+        if isinstance(total, int) and total > shown:
+            note += f" — top {shown} de {total}"
+        if not has_dims:
+            note += (" · no se pudo recuperar la muestra cruda para explicar las "
+                     "dimensiones de cada fila")
+        blocks.append(model.DataTable(
+            header=header, rows=table_rows,
+            title="Filas más atípicas", note=note))
+    return blocks
+
+
+# --------------------------------------------------------------------------- #
+# Interpretation section.
+# --------------------------------------------------------------------------- #
+def _interpretation_block(mark: bool) -> model.Markdown:
+    outlier = _term(mark, "outlier", "atípico")
+    text = (
+        f"**Un {outlier} no es necesariamente un error.** Conviene distinguir "
+        "dos casos antes de actuar:\n\n"
+        "- **Error de dato** (medida, registro o unidad equivocada): una edad de "
+        "200 años, un importe negativo donde no puede haberlo, un decimal "
+        "desplazado. Estos sí se corrigen o se eliminan, idealmente en el origen.\n"
+        "- **Dato real extremo**: una observación legítima de la cola de la "
+        "distribución (un cliente que gasta mucho más, una tarifa de lujo, un día "
+        "de ventas excepcional). Borrarla sesga el análisis y oculta información "
+        "valiosa.\n\n"
+        "**Qué hacer.** Primero, **revisar** los valores señalados arriba contra "
+        "su origen para decidir cuál de los dos casos es. Si son errores, "
+        "corregirlos. Si son datos reales que distorsionan medias y modelos, hay "
+        "alternativas a borrarlos: **winsorizar** (recortar los extremos a un "
+        "percentil), o **re-expresar** la variable (por ejemplo una "
+        "transformación logarítmica o la escalera de re-expresión de Tukey que "
+        "este mismo perfil ya calcula para las columnas asimétricas), que suele "
+        "domar la cola sin perder ninguna fila. La elección depende del objetivo: "
+        "esta lectura es **exploratoria** —orienta dónde mirar—, no una regla "
+        "automática de limpieza.")
+    return model.Markdown(text=text)
+
+
+# --------------------------------------------------------------------------- #
+# Entry point.
+# --------------------------------------------------------------------------- #
+def build_outliers(profile: dict, ctx: dict):
+    """Build the OUTLIERS Chapter, or None if the dataset has no numeric column."""
+    profile = profile or {}
+    ctx = ctx or {}
+    if not isinstance(profile, dict):
+        return None
+
+    numerics = _numeric_columns(profile)
+    if not numerics:
+        return None  # chapter does not apply to a dataset with no numerics.
+
+    # Register glossary terms (if a collector is present) and mark them clickable.
+    glossary = ctx.get("glossary")
+    mark = False
+    if isinstance(glossary, model.GlossaryCollector):
+        for key, (label, definition) in _TERM_DEFS.items():
+            glossary.add(key, label, definition)
+        mark = True
+
+    raw_numeric = ctx.get("raw_numeric")
+    raw_numeric = raw_numeric if isinstance(raw_numeric, dict) else {}
+
+    box_fn = _load_build_boxplot_stats()
+    detect_fn = _load_detect_outliers()
+
+    # --- Univariate summary ------------------------------------------------- #
+    uni_rows = []
+    for name, numeric in numerics:
+        uni_rows.append(_univariate_row(
+            name, numeric, raw_numeric.get(name), box_fn, detect_fn))
+    # Rank columns by contamination (Tukey % when available, else z %).
+    uni_rows.sort(key=lambda r: r.get("contamination", -1.0), reverse=True)
+
+    intro = (
+        "Este capítulo reúne en un solo sitio el análisis de los **valores "
+        "atípicos** de la tabla, que en el resto del informe aparecen dispersos. "
+        f"Un {_term(mark, 'outlier', 'atípico')} es una observación que se aparta "
+        "mucho del grueso de los datos. Cada columna numérica se evalúa con dos "
+        f"criterios complementarios: las {_term(mark, 'tukey_fence', 'vallas de Tukey')} "
+        "(fuera de P25−1,5·IQR o P75+1,5·IQR, robusto a la propia cola) y el "
+        f"{_term(mark, 'zscore', 'z-score')} (|z| > 3, sensible a la media). La "
+        "tabla está ordenada de la columna más contaminada a la menos.")
+
+    blocks = [
+        model.Heading(text=CHAPTER_TITLE, level=1),
+        model.Markdown(text=intro),
+        _univariate_table(uni_rows),
+    ]
+
+    # Flag the most contaminated columns explicitly.
+    flagged = [r["name"] for r in uni_rows
+               if r.get("contamination", -1.0) > 0][:_TOP_FLAGGED]
+    if flagged:
+        names = ", ".join(f"**{n}**" for n in flagged)
+        blocks.append(model.Markdown(text=(
+            f"Las columnas con mayor proporción de atípicos son {names}: "
+            "concentran el grueso de los valores fuera de las vallas y son las "
+            "primeras a revisar.")))
+
+    # --- Boxplots figure ---------------------------------------------------- #
+    box_entries = [
+        {"name": r["name"], "box": r["box"], "fliers": r.get("fliers")}
+        for r in uni_rows
+        if r.get("box")
+    ][:_TOP_BOX]
+    if box_entries:
+        def _boxplots_make(entries=box_entries):
+            try:
+                from datascience.build_boxplots_figure import build_boxplots_figure
+                return build_boxplots_figure(
+                    entries, title="Boxplots de Tukey por columna",
+                    max_boxes=_TOP_BOX)
+            except Exception:  # noqa: BLE001 — minimal fallback figure.
+                import matplotlib
+                matplotlib.use("Agg")
+                from matplotlib.figure import Figure
+                fig = Figure(figsize=(5.0, 2.2))
+                ax = fig.add_subplot(111)
+                ax.text(0.5, 0.5, "(boxplots no disponibles)",
+                        ha="center", va="center")
+                ax.axis("off")
+                return fig
+
+        blocks.append(model.Group(blocks=[
+            model.Heading(text="Boxplots", level=2),
+            model.Markdown(text=(
+                "Cada caja abarca del primer al tercer cuartil (P25–P75), la línea "
+                "interior es la mediana y los bigotes llegan hasta 1,5·IQR; los "
+                "puntos son los valores que caen fuera de las vallas (atípicos por "
+                "Tukey).")),
+            model.Figure(
+                make=_boxplots_make,
+                caption="Boxplots de Tukey de las columnas más contaminadas."),
+        ]))
+
+    # --- Multivariate ------------------------------------------------------- #
+    outliers, _src = _resolve_multivariate(profile, ctx, raw_numeric)
+    if outliers is not None:
+        blocks.extend(_multivariate_blocks(outliers, raw_numeric, mark))
+    else:
+        blocks.append(model.Heading(text="Filas atípicas (multivariante)", level=2))
+        blocks.append(model.Note(
+            "No se pudo analizar la anomalía multivariante: hacen falta al menos "
+            "dos columnas numéricas y la muestra cruda (o los modelos del perfil) "
+            "para correr Isolation Forest."))
+
+    # --- Interpretation ----------------------------------------------------- #
+    blocks.append(model.Heading(text="Cómo interpretar los atípicos", level=2))
+    blocks.append(_interpretation_block(mark))
+
+    return model.Chapter(id=CHAPTER_ID, title=CHAPTER_TITLE,
+                         version=CHAPTER_VERSION, blocks=blocks)

python/functions/datascience/automatic_eda/chapters/outliers_test.py

@@ -0,0 +1,304 @@
+"""Tests for the OUTLIERS chapter — DoD: golden + edges + error path.
+
+Self-contained: builds synthetic ``numeric`` blocks + a raw_numeric sample (no
+DuckDB) so the suite is fast and deterministic. Verifies that the chapter emits
+the univariate per-column table, a boxplots figure, the multivariate Isolation
+Forest section and the outlier≠error interpretation; that the most contaminated
+column is ranked first; that a profile with no numeric column yields None; that
+None/empty never raises; that the glossary terms are registered; and that the
+chapter renders into both PDF and PPTX without cutting its title.
+"""
+
+import math
+import os
+import re
+import tempfile
+
+from pypdf import PdfReader
+
+from datascience.automatic_eda.chapters.outliers import (
+    build_outliers, CHAPTER_VERSION, CHAPTER_TITLE, _TERM_DEFS,
+)
+from datascience.automatic_eda import model
+from datascience.render_automatic_eda_pdf import render_automatic_eda_pdf
+from datascience.render_automatic_eda_pptx import render_automatic_eda_pptx
+
+
+def _percentile(sorted_vals, q):
+    """Linear-interpolation percentile (q in 0..1) on an already-sorted list."""
+    if not sorted_vals:
+        return None
+    if len(sorted_vals) == 1:
+        return float(sorted_vals[0])
+    pos = q * (len(sorted_vals) - 1)
+    lo = int(math.floor(pos))
+    hi = int(math.ceil(pos))
+    if lo == hi:
+        return float(sorted_vals[lo])
+    frac = pos - lo
+    return float(sorted_vals[lo] * (1 - frac) + sorted_vals[hi] * frac)
+
+
+def _col_from_values(values, nbins=10):
+    """Build a ``numeric`` sub-block shaped like describe_numeric's output from a
+    concrete list of raw values, so the profile percentiles and the raw sample
+    are consistent (the boxplot fences match the crudo)."""
+    vals = [float(v) for v in values]
+    s = sorted(vals)
+    n = len(s)
+    mean = sum(vals) / n
+    var = sum((v - mean) ** 2 for v in vals) / n
+    std = math.sqrt(var)
+    median = _percentile(s, 0.5)
+    p25 = _percentile(s, 0.25)
+    p75 = _percentile(s, 0.75)
+    mn, mx = s[0], s[-1]
+    # z-score outlier count (population), what the profile's n_outliers carries.
+    n_out = sum(1 for v in vals if std > 0 and abs((v - mean) / std) > 3.0)
+    width = (mx - mn) / nbins if mx > mn else 1.0
+    hist = [{"lo": mn + i * width, "hi": mn + (i + 1) * width, "count": 1}
+            for i in range(nbins)]
+    return {
+        "min": mn, "max": mx, "mean": mean, "median": median, "std": std,
+        "p25": p25, "p50": median, "p75": p75, "iqr": (p75 - p25),
+        "n_outliers": n_out, "outlier_pct": 100.0 * n_out / n,
+        "distribution_type": "right-skewed", "histogram": hist,
+    }
+
+
+def _fare_values():
+    """A heavy-tailed column (most ~10-30, a few 200-512): clear Tukey/z outliers."""
+    base = [7.0 + (i % 25) for i in range(120)]      # bulk 7..31
+    tail = [180.0, 210.0, 263.0, 512.0]              # extreme upper tail
+    return base + tail
+
+
+def _age_values():
+    """A roughly symmetric column with one extreme low value."""
+    base = [22.0 + (i % 40) for i in range(120)]     # 22..61
+    return base + [80.0, 0.5, 74.0, 1.0]
+
+
+def _quiet_values():
+    """A clean column with no atypical values."""
+    return [50.0 + (i % 5) for i in range(124)]
+
+
+def _profile_and_ctx(with_models=True, with_raw=True):
+    fare = _fare_values()
+    age = _age_values()
+    quiet = _quiet_values()
+    cols = [
+        {"name": "Fare", "inferred_type": "numeric", "numeric": _col_from_values(fare)},
+        {"name": "Age", "inferred_type": "numeric", "numeric": _col_from_values(age)},
+        {"name": "Quiet", "inferred_type": "numeric", "numeric": _col_from_values(quiet)},
+        {"name": "Sexo", "inferred_type": "categorical",
+         "categorical": {"top": [{"value": "male", "count": 80}]}},
+    ]
+    profile = {"table": "titanic", "n_rows": len(fare), "n_cols": len(cols),
+               "columns": cols}
+    if with_models:
+        profile["models"] = {
+            "outliers": {
+                "n_outliers": 4, "outlier_pct": 3.2,
+                "outlier_rows": [
+                    {"row_index": 123, "score": -0.21},
+                    {"row_index": 121, "score": -0.15},
+                ],
+                "threshold": -0.02, "n_rows_used": 124, "n_features": 3,
+            }
+        }
+    ctx = {}
+    if with_raw:
+        ctx["raw_numeric"] = {"Fare": fare, "Age": age, "Quiet": quiet}
+    return profile, ctx
+
+
+def _pdf_text(path: str) -> str:
+    txt = "".join((pg.extract_text() or "") for pg in PdfReader(path).pages)
+    return re.sub(r"\s+", " ", txt)
+
+
+def _flatten(blocks):
+    out = []
+    for b in blocks:
+        if getattr(b, "kind", "") == "group":
+            out.extend(_flatten(getattr(b, "blocks", []) or []))
+        else:
+            out.append(b)
+    return out
+
+
+# --------------------------------------------------------------------------- #
+# Golden.
+# --------------------------------------------------------------------------- #
+def test_golden_estructura_y_secciones():
+    profile, ctx = _profile_and_ctx()
+    ctx["glossary"] = model.GlossaryCollector()
+    ch = build_outliers(profile, ctx)
+    assert ch is not None
+    assert ch.id == "outliers"
+    assert ch.version == CHAPTER_VERSION
+
+    flat = _flatten(ch.blocks)
+    kinds = [b.kind for b in flat]
+    # Title heading + univariate DataTable + boxplots Figure + multivariate
+    # KVTable + interpretation Markdown.
+    assert kinds[0] == "heading" and flat[0].text == CHAPTER_TITLE
+    tables = [b for b in flat if b.kind == "data_table"]
+    titles = [t.title for t in tables]
+    assert any(t and "atípicos por columna" in t for t in titles)
+    assert any(b.kind == "figure" for b in flat), "falta la figura de boxplots"
+    assert any(b.kind == "kv_table" for b in flat), "falta el resumen multivariante"
+
+    # The boxplots figure maker yields a real matplotlib figure (or its fallback).
+    fig = next(b for b in flat if b.kind == "figure").make()
+    assert fig is not None
+    import matplotlib.pyplot as plt
+    plt.close(fig)
+
+
+def test_golden_fare_es_la_mas_contaminada():
+    # The univariate table must rank Fare (heavy tail) first and report a
+    # non-zero Tukey percentage for it.
+    profile, ctx = _profile_and_ctx()
+    ch = build_outliers(profile, ctx)
+    table = next(b for b in _flatten(ch.blocks)
+                 if b.kind == "data_table" and b.title
+                 and "atípicos por columna" in b.title)
+    first_col = table.rows[0][0]
+    assert first_col == "Fare", f"esperaba Fare primera, fue {first_col}"
+    # % Tukey column (index 2) of the first row must be > 0.
+    pct_cell = table.rows[0][2]
+    assert pct_cell not in ("—", "0%", "0.00%"), f"% Tukey de Fare vacío: {pct_cell}"
+    # The z-score rule (detect_outliers) must actually run with raw_numeric: at
+    # least one column reports a non-empty z count/percentage (regression guard
+    # for the detect_outliers import path).
+    z_pcts = [r[4] for r in table.rows]
+    assert any(c not in ("—",) for c in z_pcts), f"columna z toda vacía: {z_pcts}"
+    z_counts = [r[3] for r in table.rows]
+    assert any(c not in ("—",) for c in z_counts), f"conteo z vacío: {z_counts}"
+
+
+def test_golden_interpretacion_outlier_no_es_error():
+    profile, ctx = _profile_and_ctx()
+    ch = build_outliers(profile, ctx)
+    md = " ".join(b.text for b in _flatten(ch.blocks) if b.kind == "markdown")
+    assert "no es necesariamente un error" in md.lower()
+    # Mentions the actionable options (winsorize / re-express).
+    assert "winsoriz" in md.lower()
+    assert "re-expres" in md.lower() or "logarítmic" in md.lower()
+
+
+def test_golden_terminos_glosario_registrados():
+    profile, ctx = _profile_and_ctx()
+    gloss = model.GlossaryCollector()
+    ctx["glossary"] = gloss
+    build_outliers(profile, ctx)
+    for key in _TERM_DEFS:
+        assert gloss.has(key), f"término '{key}' no registrado en el glosario"
+    # Terms are marked clickable in the body text.
+    md = " ".join(b.text for b in _flatten(build_outliers(profile, ctx).blocks)
+                  if b.kind == "markdown")
+    assert "[[term:outlier]]" in md and "[[term:tukey_fence]]" in md
+
+
+# --------------------------------------------------------------------------- #
+# Multivariate.
+# --------------------------------------------------------------------------- #
+def test_multivariante_live_con_raw_y_dims():
+    # With a raw sample the chapter runs Isolation Forest live (over the same
+    # columns summarize_outlier_dims uses) and lists the anomalous rows with the
+    # dimensions that make each one rare.
+    profile, ctx = _profile_and_ctx(with_models=False, with_raw=True)
+    ch = build_outliers(profile, ctx)
+    flat = _flatten(ch.blocks)
+    kv = next(b for b in flat if b.kind == "kv_table")
+    flat_kv = " ".join(f"{k} {v}" for (k, v) in kv.rows)
+    assert "Filas atípicas" in flat_kv
+    # A non-zero number of anomalous rows is reported.
+    n_cell = dict(kv.rows).get("Filas atípicas")
+    assert n_cell not in (None, "—", "0"), f"sin filas atípicas: {n_cell}"
+    # The anomalous-rows table carries the per-row dimension breakdown.
+    tbls = [b for b in flat if b.kind == "data_table" and b.title
+            and "más atípicas" in b.title]
+    assert tbls, "falta la tabla de filas más atípicas"
+    assert any("hacen rara" in h for h in tbls[0].header), \
+        f"falta la columna de dimensiones: {tbls[0].header}"
+
+
+def test_multivariante_precomputed_sin_raw():
+    # Without a raw sample the chapter falls back to profile['models']['outliers']
+    # (lite preset path); the precomputed n_outliers (4) surfaces in the KV table.
+    profile, ctx = _profile_and_ctx(with_models=True, with_raw=False)
+    ch = build_outliers(profile, ctx)
+    kv = next(b for b in _flatten(ch.blocks) if b.kind == "kv_table")
+    assert any("4" in str(v) for (k, v) in kv.rows)
+
+
+def test_multivariante_ausente_degrada_a_nota():
+    # No models and no raw sample → an honest note, never a crash.
+    profile, ctx = _profile_and_ctx(with_models=False, with_raw=False)
+    ch = build_outliers(profile, ctx)
+    assert ch is not None
+    notes = [b.text for b in _flatten(ch.blocks) if b.kind == "note"]
+    assert any("Isolation Forest" in n for n in notes)
+
+
+# --------------------------------------------------------------------------- #
+# Edges / error path.
+# --------------------------------------------------------------------------- #
+def test_edge_sin_columnas_numericas_devuelve_none():
+    prof = {"columns": [{"name": "c", "inferred_type": "categorical",
+                         "categorical": {"top": [{"value": "x", "count": 3}]}}]}
+    assert build_outliers(prof, {}) is None
+
+
+def test_edge_solo_texto_sintetico_devuelve_none():
+    # A text-only synthetic table (no numeric column) yields None (does not break).
+    prof = {"table": "notas", "n_rows": 3, "n_cols": 1,
+            "columns": [{"name": "comentario", "inferred_type": "text",
+                         "text": {"n_docs": 3}}]}
+    assert build_outliers(prof, {}) is None
+
+
+def test_edge_profile_none_y_vacio_no_revienta():
+    assert build_outliers(None, None) is None
+    assert build_outliers({}, {}) is None
+    assert build_outliers({"columns": []}, {}) is None
+
+
+def test_edge_sin_raw_numeric_degrada_a_perfil():
+    # Without raw_numeric the chapter still builds, using the profile z-score
+    # counts; the univariate table exists and Tukey counts degrade to '—'.
+    profile, ctx = _profile_and_ctx(with_models=True, with_raw=False)
+    ch = build_outliers(profile, ctx)
+    assert ch is not None
+    table = next(b for b in _flatten(ch.blocks)
+                 if b.kind == "data_table" and b.title
+                 and "atípicos por columna" in b.title)
+    # z column comes from the profile; Tukey count is unknown ('—').
+    assert all(len(r) == 8 for r in table.rows)
+
+
+# --------------------------------------------------------------------------- #
+# Anti-cut render.
+# --------------------------------------------------------------------------- #
+def test_render_pdf_y_pptx_incluyen_el_capitulo():
+    profile, ctx = _profile_and_ctx()
+    # The renderers build the whole document; the chapter is reached via the
+    # registry. Render the chapter standalone through a one-chapter document by
+    # passing the profile directly (the renderers run the full chapter registry).
+    with tempfile.TemporaryDirectory() as d:
+        pdf = os.path.join(d, "out.pdf")
+        res_pdf = render_automatic_eda_pdf(profile, pdf,
+                                           {"write_manifest": False, "ctx": ctx})
+        assert res_pdf["path"] == pdf
+        txt = _pdf_text(pdf)
+        assert CHAPTER_TITLE in txt, "el capítulo OUTLIERS no aparece en el PDF"
+        assert "Fare" in txt
+        pptx = os.path.join(d, "out.pptx")
+        res_pptx = render_automatic_eda_pptx(profile, pptx,
+                                             {"write_manifest": False, "ctx": ctx})
+        assert res_pptx["path"] == pptx
+        assert res_pptx["n_slides"] >= 1

python/functions/datascience/automatic_eda/chapters_registry.py

@@ -33,6 +33,8 @@ CHAPTER_ORDER = [
     "cat_distr",     # categorical distributions
     "text_distr",    # free-text / NLP distributions (non-tabular content)
     "calidad",       # data quality
+    "missingness",   # missing-data patterns (co-occurrence of absences; MCAR/MAR)
+    "outliers",      # atypical values: univariate (Tukey/z) + multivariate (IsolationForest)
     "correlacion",   # correlations / associations
     "relaciones",    # key relations: declared/candidate PK + FK (inter/intra-table)
     "modelos",       # cheap models (PCA/KMeans/outliers)

python/functions/datascience/automatic_eda/md_completeness_test.py

@@ -0,0 +1,253 @@
+"""Tests for the Markdown completeness appendix (report 2053).
+
+The AutomaticEDA Markdown is the output meant to be *pasted into an LLM*, so it
+must carry EVERYTHING the engine computed — even the numbers the human-facing
+chapters (shared with the PDF/PPTX) drop for readability. ``render_md`` appends a
+full-data appendix built from ``meta['profile']`` that closes the six losses the
+evaluation found:
+
+1. the complete association matrix (every pair, incl. correlation_ratio /
+   cramers_v) — not just the top extremes;
+2. every numeric statistic for every numeric column (skew/kurtosis/percentiles);
+3. the concrete recommended re-expression;
+4. KMeans ``scores_by_k``;
+5. the normality test statistics;
+6. correct headers for bar/scree figure tables (not ``Desde/Hasta/Frecuencia``).
+
+Self-contained: a synthetic profile, no DuckDB, no heavy renderer.
+"""
+
+import os
+import sys
+
+import pytest  # noqa: F401
+
+_HERE = os.path.dirname(os.path.abspath(__file__))
+_FUNCTIONS = os.path.abspath(os.path.join(_HERE, "..", "..", ".."))  # python/functions
+if _FUNCTIONS not in sys.path:
+    sys.path.insert(0, _FUNCTIONS)
+
+from datascience.automatic_eda import model  # noqa: E402
+from datascience.automatic_eda.render_md_impl import (  # noqa: E402
+    _bars_table,
+    _is_histogram_caption,
+    _profile_appendix,
+    render_md,
+)
+
+
+# --------------------------------------------------------------------------- #
+# Synthetic profile fixtures.
+# --------------------------------------------------------------------------- #
+def _numeric(skew, kurtosis):
+    """A numeric stat block with every key the appendix serializes."""
+    return {
+        "count": 100, "min": 0.0, "max": 10.0, "mean": 5.0, "median": 5.0,
+        "mode": 4.0, "std": 2.0, "variance": 4.0, "cv": 0.4,
+        "p1": 0.1, "p5": 0.5, "p25": 2.5, "p50": 5.0, "p75": 7.5,
+        "p95": 9.5, "p99": 9.9, "iqr": 5.0, "skew": skew, "kurtosis": kurtosis,
+        "n_outliers": 1, "distribution_type": "normal",
+    }
+
+
+def _profile():
+    """A small but structurally faithful TableProfile (3 numeric, 2 categorical)."""
+    pairs = [
+        {"a": "A", "b": "B", "a_type": "numeric", "b_type": "numeric",
+         "method": "pearson/spearman", "value": 0.8,
+         "p_value": 1e-9, "p_value_adjusted": 2e-9, "significant": True},
+        {"a": "A", "b": "C", "a_type": "numeric", "b_type": "numeric",
+         "method": "pearson/spearman", "value": -0.3,
+         "p_value": 0.01, "p_value_adjusted": 0.02, "significant": True},
+        {"a": "A", "b": "Cat1", "a_type": "numeric", "b_type": "categorical",
+         "method": "correlation_ratio", "value": 0.45,
+         "p_value": 0.001, "p_value_adjusted": 0.002, "significant": True},
+        # The single cat-cat pair the human chapter never shows.
+        {"a": "Cat1", "b": "Cat2", "a_type": "categorical",
+         "b_type": "categorical", "method": "cramers_v", "value": 0.11,
+         "p_value": 0.04, "p_value_adjusted": 0.05, "significant": False},
+    ]
+    return {
+        "correlations": {
+            "pairs": pairs,
+            "multiple_testing": {"method": "bh", "n_tests": 4, "n_rejected": 3},
+        },
+        "columns": [
+            {"name": "A", "count": 100, "numeric": _numeric(0.0, -1.2),
+             "reexpression": {"recommended": "none", "ladder_power": 1.0,
+                              "reason": "symmetric", "alternatives": []}},
+            {"name": "B", "count": 100, "numeric": _numeric(4.77, 33.1),
+             "reexpression": {"recommended": "log1p", "ladder_power": 0.0,
+                              "reason": "skew 4.77 with zeros",
+                              "alternatives": [{"transform": "yeo-johnson"},
+                                               {"transform": "sqrt"}]}},
+            {"name": "C", "count": 100, "numeric": _numeric(-0.6, 0.2)},
+            {"name": "Cat1", "categorical": {"top": [], "mode": "x"}},
+            {"name": "Cat2", "categorical": {"top": [], "mode": "y"}},
+        ],
+        "models": {
+            "kmeans": {
+                "best_k": 3,
+                "scores_by_k": [
+                    {"k": 2, "silhouette": 0.46, "inertia": 900.0},
+                    {"k": 3, "silhouette": 0.50, "inertia": 550.0},
+                    {"k": 4, "silhouette": 0.38, "inertia": 430.0},
+                ],
+                "cluster_sizes": [40, 35, 25],
+            },
+            "normality": {
+                "A": {"n": 100,
+                      "jarque_bera": {"stat": 18.7, "p": 8e-5, "normal": False},
+                      "dagostino": {"stat": 18.1, "p": 1e-4, "normal": False},
+                      "shapiro": {"stat": 0.98, "p": 7e-8, "normal": False},
+                      "is_normal": False},
+                "C": {"n": 100,
+                      "jarque_bera": {"stat": 2.1, "p": 0.35, "normal": True},
+                      "dagostino": {"stat": 1.9, "p": 0.38, "normal": True},
+                      "shapiro": {"stat": 0.99, "p": 0.12, "normal": True},
+                      "is_normal": True},
+            },
+        },
+    }
+
+
+def _dummy_chapters():
+    """A minimal one-chapter document so render_md does not early-return empty."""
+    return model.as_chapters([
+        {"id": "intro", "title": "Intro",
+         "blocks": [{"kind": "markdown", "text": "cuerpo del informe"}]},
+    ])
+
+
+def _render(tmp_path, profile):
+    out = os.path.join(str(tmp_path), "out.md")
+    res = render_md(_dummy_chapters(), out, {"title": "EDA — t", "profile": profile})
+    assert res["path"] == out
+    return open(out, encoding="utf-8").read()
+
+
+def _table_rows(md, section_title):
+    """Count data rows of the first Markdown table under ``section_title``."""
+    seg = md.split(section_title, 1)[1]
+    rows, in_t, seen_sep = 0, False, False
+    for ln in seg.splitlines():
+        if ln.startswith("|"):
+            in_t = True
+            stripped = ln.replace("|", "").replace(" ", "")
+            if stripped and set(stripped) == {"-"}:
+                seen_sep = True
+                continue
+            if seen_sep:
+                rows += 1
+        elif in_t and not ln.strip():
+            break
+    return rows
+
+
+# --------------------------------------------------------------------------- #
+# Golden: every datum the profile holds reaches the .md.
+# --------------------------------------------------------------------------- #
+def test_appendix_lists_all_correlation_pairs(tmp_path):
+    md = _render(tmp_path, _profile())
+    assert "## Apéndice — Datos completos del perfil" in md
+    # All 4 pairs (the real titanic profile has 28; here 4 synthetic).
+    assert _table_rows(md, "### Matriz de asociación") == 4
+    # The cat-cat Cramér's V pair the human chapter drops is present.
+    assert "Cat1 ↔ Cat2" in md
+    assert "cramers_v" in md
+    assert "correlation_ratio" in md
+
+
+def test_appendix_has_skew_kurtosis_for_every_numeric(tmp_path):
+    md = _render(tmp_path, _profile())
+    seg = md.split("### Estadísticos numéricos completos", 1)[1].split("###", 1)[0]
+    lines = [l for l in seg.splitlines() if l.startswith("|")]
+    header = [h.strip() for h in lines[0].strip("|").split("|")]
+    assert "skew" in header and "kurtosis" in header
+    ski, kui = header.index("skew"), header.index("kurtosis")
+    data = lines[2:]  # skip header + separator
+    assert len(data) == 3  # exactly the 3 numeric columns
+    for row in data:
+        cells = [c.strip() for c in row.strip("|").split("|")]
+        assert cells[ski] != "", f"missing skew in {cells[0]}"
+        assert cells[kui] != "", f"missing kurtosis in {cells[0]}"
+
+
+def test_appendix_has_extended_percentiles(tmp_path):
+    md = _render(tmp_path, _profile())
+    seg = md.split("### Estadísticos numéricos completos", 1)[1]
+    header = [h.strip() for h in seg.splitlines()[2].strip("|").split("|")]
+    for p in ("p1", "p5", "p25", "p75", "p95", "p99"):
+        assert p in header, f"percentile {p} missing from describe header"
+
+
+def test_appendix_names_concrete_reexpression(tmp_path):
+    md = _render(tmp_path, _profile())
+    assert "### Re-expresión recomendada" in md
+    assert "log1p" in md  # the concrete transform, not just "consider re-expressing"
+    assert "yeo-johnson" in md  # alternatives listed too
+
+
+def test_appendix_has_kmeans_scores_by_k(tmp_path):
+    md = _render(tmp_path, _profile())
+    assert "scores_by_k" in md
+    assert _table_rows(md, "#### KMeans — selección de k") == 3  # k=2,3,4
+
+
+def test_appendix_has_normality_statistics(tmp_path):
+    md = _render(tmp_path, _profile())
+    assert "JB stat" in md  # the statistic, not only the p-value
+    assert "Shapiro stat" in md
+    assert _table_rows(md, "#### Tests de normalidad") == 2  # cols A and C
+
+
+# --------------------------------------------------------------------------- #
+# Edge: a profile missing models / correlations degrades, never raises.
+# --------------------------------------------------------------------------- #
+def test_lite_profile_without_models(tmp_path):
+    prof = _profile()
+    prof.pop("models")  # lite: no KMeans/normality
+    md = _render(tmp_path, prof)
+    assert "scores_by_k" not in md  # section skipped
+    assert "Matriz de asociación" in md  # correlations still dumped
+    assert "## Apéndice" in md
+
+
+def test_profile_without_correlations(tmp_path):
+    prof = _profile()
+    prof.pop("correlations")
+    md = _render(tmp_path, prof)  # must not raise
+    assert "Matriz de asociación" not in md
+    assert "Estadísticos numéricos completos" in md  # numeric section still there
+
+
+def test_no_profile_means_no_appendix(tmp_path):
+    out = os.path.join(str(tmp_path), "noprof.md")
+    res = render_md(_dummy_chapters(), out, {"title": "x"})
+    assert res["path"] == out
+    assert "## Apéndice" not in open(out, encoding="utf-8").read()
+
+
+def test_appendix_helper_is_defensive():
+    assert _profile_appendix(None) == ""
+    assert _profile_appendix({}) == ""
+    assert _profile_appendix({"columns": []}) == ""
+
+
+# --------------------------------------------------------------------------- #
+# Loss #6: bar/scree figure tables get a non-misleading header.
+# --------------------------------------------------------------------------- #
+def test_histogram_caption_detection():
+    assert _is_histogram_caption("Histograma de Age")
+    assert _is_histogram_caption("Distribución de Fare")
+    assert not _is_histogram_caption("Media de Survived por Sex")
+    assert not _is_histogram_caption("Varianza explicada (scree PCA)")
+
+
+def test_bars_table_custom_header():
+    bars = [(0.0, 1.0, 5.0), (1.0, 2.0, 3.0)]
+    hist = _bars_table(bars)  # default histogram header
+    assert "| Desde | Hasta | Frecuencia |" in hist
+    bar = _bars_table(bars, ("Inicio", "Fin", "Valor"))
+    assert "| Inicio | Fin | Valor |" in bar
+    assert "Frecuencia" not in bar

python/functions/datascience/automatic_eda/render_md_impl.py

@@ -178,9 +178,17 @@ def _md_data_table(block) -> str:
     return "\n".join(lines)
 
 
-def _bars_table(bars: list) -> str:
-    """Render extracted bar/histogram data as a Markdown table (Desde/Hasta/Frec)."""
-    lines = ["| Desde | Hasta | Frecuencia |", "| --- | --- | --- |"]
+def _bars_table(bars: list, header: tuple = ("Desde", "Hasta", "Frecuencia")) -> str:
+    """Render extracted bar/histogram data as a Markdown table.
+
+    ``header`` is the 3-column header to use. Histogram bars are
+    ``(Desde, Hasta, Frecuencia)``; bar/scree charts (means by group, PCA
+    explained variance) are *not* bins, so the caller passes a semantically
+    correct header (e.g. ``(Inicio, Fin, Valor)``) to avoid the misleading
+    "Frecuencia" label — see report 2053, loss #6.
+    """
+    h0, h1, h2 = header
+    lines = [f"| {h0} | {h1} | {h2} |", "| --- | --- | --- |"]
     shown = bars[:_MAX_BAR_ROWS]
     for x0, x1, h in shown:
         lines.append(f"| {_fmt_num(x0)} | {_fmt_num(x1)} | {_fmt_num(h)} |")
@@ -191,6 +199,18 @@ def _bars_table(bars: list) -> str:
     return out
 
 
+def _is_histogram_caption(caption: str) -> bool:
+    """True when a figure caption describes a histogram (genuine numeric bins).
+
+    Histograms are the only figures whose bars are real ``[Desde, Hasta)`` bins
+    with a frequency count. Bar charts (means by group) and the PCA scree plot
+    carry per-category / per-component values, not bins — they must not inherit
+    the ``Desde/Hasta/Frecuencia`` header.
+    """
+    c = (caption or "").lower()
+    return "histograma" in c or "distribución" in c or "distribucion" in c
+
+
 def _extract_bars(fig) -> list:
     """Collect (x_from, x_to, height) of the rectangular bars of a matplotlib fig.
 
@@ -253,7 +273,13 @@ def _md_figure(block, meta: dict, out_path: str, counter: list) -> str:
         if fig is not None:
             bars = _extract_bars(fig)
             if bars:
-                parts.append(_bars_table(bars))
+                # A histogram's bars are genuine numeric bins (Desde/Hasta/
+                # Frecuencia). Bar charts and the PCA scree plot are not bins —
+                # give them a header that does not lie about "Frecuencia".
+                header = (("Desde", "Hasta", "Frecuencia")
+                          if _is_histogram_caption(caption)
+                          else ("Inicio", "Fin", "Valor"))
+                parts.append(_bars_table(bars, header))
             if meta.get("embed_figures"):
                 png = _embed_png(fig, out_path, counter)
                 if png:
@@ -354,6 +380,258 @@ def _serialize_block(block, meta: dict, out_path: str, counter: list) -> str:
     return _md_note(model.Note(text=model._safe_str(block)))
 
 
+# --------------------------------------------------------------------------- #
+# Profile appendix — the data the human-facing chapters drop.
+#
+# The chapter document (shared with the PDF/PPTX renderers) is designed for human
+# reading and intentionally omits raw numbers: the correlation matrix shows only
+# the top extremes, the numeric blocks skip skew/kurtosis/extended percentiles,
+# the model chapter does not list ``scores_by_k`` or the normality test
+# statistics. But the Markdown is meant to be *pasted into an LLM*, so it should
+# carry EVERYTHING the engine computed. This appendix serializes the full
+# ``profile`` (passed via ``meta['profile']``) as Markdown tables, additively:
+# the PDF/PPTX are untouched, the .md simply has more than they do. Each section
+# is emitted only when its source data is present, so a ``lite`` profile (no
+# models) or a profile without correlations degrades cleanly instead of raising.
+# See report 2053 for the six losses this closes.
+# --------------------------------------------------------------------------- #
+def _pair_types(a_type, b_type) -> str:
+    """Short ``num↔cat`` label for an association pair's variable types."""
+    def short(t):
+        t = model._safe_str(t).lower()
+        if t.startswith("num"):
+            return "num"
+        if t.startswith("cat"):
+            return "cat"
+        return t or "?"
+    return f"{short(a_type)}↔{short(b_type)}"
+
+
+def _app_correlations(corr: dict) -> str:
+    """Loss #1 — every association pair (not just the top extremes).
+
+    Dumps all of ``correlations['pairs']`` as a table (pair · types · method ·
+    value · p · p-FDR · significant), ordered by |value| desc so the strongest
+    associations lead while nothing is cut. Includes the ``correlation_ratio``
+    (num↔cat) and ``cramers_v`` (cat↔cat) pairs the human chapter never shows.
+    """
+    pairs = list(corr.get("pairs", []) or [])
+    if not pairs:
+        return ""
+    def keyfn(p):
+        try:
+            return -abs(float(p.get("value")))
+        except Exception:  # noqa: BLE001
+            return 0.0
+    pairs_sorted = sorted(pairs, key=keyfn)
+    lines = ["### Matriz de asociación — todos los pares",
+             "",
+             ("| Par | Tipos | Método | Valor | p-value | p-ajustado (FDR) "
+              "| ¿Sig? |"),
+             "| --- | --- | --- | --- | --- | --- | --- |"]
+    for p in pairs_sorted:
+        par = f"{_cell(p.get('a'))} ↔ {_cell(p.get('b'))}"
+        types = _pair_types(p.get("a_type"), p.get("b_type"))
+        method = _cell(p.get("method"))
+        val = _fmt_num(p.get("value"))
+        pv = _fmt_num(p.get("p_value")) if p.get("p_value") is not None else ""
+        padj = (_fmt_num(p.get("p_value_adjusted"))
+                if p.get("p_value_adjusted") is not None else "")
+        sig = "sí" if p.get("significant") else "no"
+        lines.append(
+            f"| {par} | {types} | {method} | {val} | {pv} | {padj} | {sig} |")
+    mt = corr.get("multiple_testing") or {}
+    n_tests = mt.get("n_tests", corr.get("n_tests"))
+    n_rej = mt.get("n_rejected")
+    note_bits = [f"{len(pairs)} pares en total"]
+    if n_tests is not None and n_rej is not None:
+        note_bits.append(
+            f"{n_rej} de {n_tests} significativos tras corrección "
+            f"{model._safe_str(mt.get('method', 'FDR')).upper()}")
+    lines.append("")
+    lines.append(f"*{'; '.join(note_bits)}.*")
+    return "\n".join(lines)
+
+
+# Numeric statistics, in serialization order: (profile key, column header).
+_NUM_STATS = [
+    ("count", "n"), ("mean", "mean"), ("median", "median"), ("mode", "mode"),
+    ("std", "std"), ("variance", "variance"), ("cv", "cv"),
+    ("skew", "skew"), ("kurtosis", "kurtosis"),
+    ("min", "min"), ("p1", "p1"), ("p5", "p5"), ("p25", "p25"), ("p50", "p50"),
+    ("p75", "p75"), ("p95", "p95"), ("p99", "p99"), ("iqr", "iqr"),
+    ("max", "max"), ("n_outliers", "outliers"),
+    ("distribution_type", "distribución"),
+]
+
+
+def _app_numeric_describe(columns: list) -> str:
+    """Loss #2 — every numeric statistic for every numeric column.
+
+    One row per numeric column with the full describe: mean/median/mode/std/
+    variance/cv, skew & kurtosis (for ALL columns, not only the skewed ones),
+    p1/p5/p25/p50/p75/p95/p99, iqr, min/max, outliers and distribution_type.
+    """
+    rows = []
+    for info in (columns or []):
+        num = info.get("numeric") if isinstance(info, dict) else None
+        if not num:
+            continue
+        name = _cell(info.get("name"))
+        cells = [name]
+        for key, _hdr in _NUM_STATS:
+            v = num.get("count" if key == "count" else key)
+            if key == "count":
+                v = num.get("count", info.get("count"))
+            if key == "distribution_type":
+                cells.append(_cell(v))
+            else:
+                cells.append(_fmt_num(v) if v is not None else "")
+        rows.append(cells)
+    if not rows:
+        return ""
+    header = ["Columna"] + [hdr for _k, hdr in _NUM_STATS]
+    lines = ["### Estadísticos numéricos completos (describe)",
+             "",
+             "| " + " | ".join(header) + " |",
+             "| " + " | ".join(["---"] * len(header)) + " |"]
+    for cells in rows:
+        lines.append("| " + " | ".join(cells) + " |")
+    return "\n".join(lines)
+
+
+def _app_reexpression(columns: list) -> str:
+    """Loss #3 — the concrete recommended re-expression per column.
+
+    Names the transform (log1p/sqrt/yeo-johnson/none) instead of a vague
+    "consider re-expressing", with the ladder power, reason and alternatives.
+    """
+    rows = []
+    for info in (columns or []):
+        rx = info.get("reexpression") if isinstance(info, dict) else None
+        if not rx or not isinstance(rx, dict):
+            continue
+        rec = model._safe_str(rx.get("recommended")).strip()
+        if not rec:
+            continue
+        alts = rx.get("alternatives") or []
+        alt_txt = ", ".join(
+            model._safe_str(a.get("transform")) for a in alts
+            if isinstance(a, dict) and a.get("transform")) or "—"
+        rows.append([
+            _cell(info.get("name")), _cell(rec),
+            _fmt_num(rx.get("ladder_power")) if rx.get("ladder_power") is not None else "",
+            _cell(rx.get("reason")), _cell(alt_txt),
+        ])
+    if not rows:
+        return ""
+    lines = ["### Re-expresión recomendada (escalera de Tukey)",
+             "",
+             "| Columna | Recomendada | Potencia | Razón | Alternativas |",
+             "| --- | --- | --- | --- | --- |"]
+    for r in rows:
+        lines.append("| " + " | ".join(r) + " |")
+    return "\n".join(lines)
+
+
+def _app_kmeans_scores(kmeans: dict) -> str:
+    """Loss #4 — KMeans silhouette + inertia per k (justifies the chosen k)."""
+    scores = list(kmeans.get("scores_by_k", []) or [])
+    if not scores:
+        return ""
+    best_k = kmeans.get("best_k")
+    lines = ["#### KMeans — selección de k (`scores_by_k`)",
+             "",
+             "| k | Silhouette | Inercia | Elegido |",
+             "| --- | --- | --- | --- |"]
+    for s in scores:
+        if not isinstance(s, dict):
+            continue
+        k = s.get("k")
+        chosen = "✓" if best_k is not None and k == best_k else ""
+        lines.append(
+            f"| {_fmt_num(k)} | {_fmt_num(s.get('silhouette'))} "
+            f"| {_fmt_num(s.get('inertia'))} | {chosen} |")
+    return "\n".join(lines)
+
+
+def _app_normality(normality: dict) -> str:
+    """Loss #5 — each normality test's statistic next to its p-value."""
+    if not isinstance(normality, dict) or not normality:
+        return ""
+    lines = ["#### Tests de normalidad (estadístico + p-value)",
+             "",
+             ("| Columna | n | JB stat | JB p | D'Agostino stat | D'Agostino p "
+              "| Shapiro stat | Shapiro p | ¿Normal? |"),
+             "| --- | --- | --- | --- | --- | --- | --- | --- | --- |"]
+    any_row = False
+    for col, res in normality.items():
+        if not isinstance(res, dict):
+            continue
+        jb = res.get("jarque_bera") or {}
+        da = res.get("dagostino") or {}
+        sh = res.get("shapiro") or {}
+        is_norm = "sí" if res.get("is_normal") else "no"
+        lines.append(
+            f"| {_cell(col)} | {_fmt_num(res.get('n')) if res.get('n') is not None else ''} "
+            f"| {_fmt_num(jb.get('stat'))} | {_fmt_num(jb.get('p'))} "
+            f"| {_fmt_num(da.get('stat'))} | {_fmt_num(da.get('p'))} "
+            f"| {_fmt_num(sh.get('stat'))} | {_fmt_num(sh.get('p'))} | {is_norm} |")
+        any_row = True
+    return "\n".join(lines) if any_row else ""
+
+
+def _profile_appendix(profile: dict) -> str:
+    """Build the full-data appendix from a TableProfile dict (additive).
+
+    Returns a Markdown ``## Apéndice`` section with one sub-table per loss the
+    human chapters drop, or ``""`` when the profile carries none of them. Never
+    raises: a missing/oddly-shaped section is skipped, not fatal.
+    """
+    if not isinstance(profile, dict):
+        return ""
+    sections: list = []
+    try:
+        corr = profile.get("correlations") or {}
+        seg = _app_correlations(corr) if isinstance(corr, dict) else ""
+        if seg:
+            sections.append(seg)
+    except Exception:  # noqa: BLE001
+        pass
+    try:
+        columns = profile.get("columns") or []
+        seg = _app_numeric_describe(columns)
+        if seg:
+            sections.append(seg)
+        seg = _app_reexpression(columns)
+        if seg:
+            sections.append(seg)
+    except Exception:  # noqa: BLE001
+        pass
+    try:
+        models = profile.get("models") or {}
+        if isinstance(models, dict):
+            model_segs = []
+            seg = _app_kmeans_scores(models.get("kmeans") or {})
+            if seg:
+                model_segs.append(seg)
+            seg = _app_normality(models.get("normality") or {})
+            if seg:
+                model_segs.append(seg)
+            if model_segs:
+                sections.append(
+                    "### Modelos — detalle\n\n" + "\n\n".join(model_segs))
+    except Exception:  # noqa: BLE001
+        pass
+    if not sections:
+        return ""
+    intro = ("Volcado completo de los datos que el motor computó y que los "
+             "capítulos (pensados para lectura humana / PDF) resumen. "
+             "Pensado para que un LLM reconstruya el análisis entero.")
+    return ("## Apéndice — Datos completos del perfil\n\n"
+            f"*{intro}*\n\n" + "\n\n".join(sections))
+
+
 # --------------------------------------------------------------------------- #
 # Entry point.
 # --------------------------------------------------------------------------- #
@@ -437,6 +715,18 @@ def render_md(chapters: list, out_path: str, meta: dict = None) -> dict:
                 segments.append(seg)
         chapters_meta.append({"id": ch.id, "version": ch.version})
 
+    # Full-data appendix: dump everything the profile holds that the human
+    # chapters drop (additive — the .md ends up with more than the PDF/PPTX).
+    # Emitted only when a profile is supplied via meta['profile']; never fatal.
+    try:
+        appendix = _profile_appendix(meta.get("profile"))
+    except Exception as e:  # noqa: BLE001
+        appendix = ""
+        notes.append(f"apéndice de perfil omitido: {e}")
+    if appendix:
+        segments.append("---")
+        segments.append(appendix)
+
     content = "\n\n".join(segments) + "\n"
     note = f"{len(content)} caracteres"
     if notes:

python/functions/datascience/build_boxplots_figure.md

@@ -0,0 +1,125 @@
+---
+id: build_boxplots_figure_py_datascience
+name: build_boxplots_figure
+kind: function
+lang: py
+domain: datascience
+version: "1.0.0"
+purity: impure
+signature: "def build_boxplots_figure(boxes: list, title: str = \"\", max_boxes: int = 12) -> \"matplotlib.figure.Figure\""
+description: "Construye una unica figura matplotlib con boxplots de Tukey HORIZONTALES (uno por columna) usando ax.bxp: caja Q1-Q3, bigotes hasta 1.5*IQR, linea de mediana y puntos atipicos. Consume la salida de build_boxplot_stats (un dict box por columna, leido con .get) mas una lista opcional de outliers crudos por columna; si vienen los dibuja como puntos (showfliers), si no marca solo box[min]/box[max] cuando hay outliers de cola (igual que num_distr). Dibuja como mucho max_boxes cajas (las primeras, ya ordenadas por contaminacion por el caller) y avisa de la truncacion con (mostrando N de M). Backend Agg sin pyplot global; alto adaptativo al nº de cajas. Defensiva: omite entradas invalidas y NUNCA lanza — sin cajas validas devuelve una figura placeholder (sin boxplots). Es la version small-multiples del capitulo num_distr para responder que columnas tienen mas outliers de un vistazo."
+tags: [eda, outliers, boxplot, tukey, iqr, bxp, matplotlib, figure, visualization, small-multiples, datascience, impure]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: [matplotlib]
+example: |
+  from datascience.build_boxplot_stats import build_boxplot_stats
+  from datascience.build_boxplots_figure import build_boxplots_figure
+  boxes = [
+      {"name": "ingresos", "box": build_boxplot_stats({"min": 1.0, "max": 9e3,
+          "p25": 1e3, "median": 2e3, "p75": 3e3, "n_outliers": 7}), "fliers": None},
+      {"name": "edad", "box": build_boxplot_stats({"min": 0.0, "max": 99.0,
+          "p25": 25.0, "median": 38.0, "p75": 52.0}), "fliers": None},
+  ]
+  fig = build_boxplots_figure(boxes, title="Outliers por columna", max_boxes=12)
+tested: true
+tests:
+  - "test_returns_figure_with_axes"
+  - "test_empty_list_returns_placeholder_figure"
+  - "test_invalid_box_is_skipped_not_raised"
+  - "test_all_invalid_returns_placeholder"
+  - "test_raw_fliers_are_drawn"
+  - "test_max_boxes_truncates_and_does_not_raise"
+test_file_path: "python/functions/datascience/build_boxplots_figure_test.py"
+file_path: "python/functions/datascience/build_boxplots_figure.py"
+params:
+  - name: boxes
+    desc: "Lista de dicts, cada uno {\"name\": str, \"box\": dict, \"fliers\": list|None}. box es EXACTAMENTE la salida de build_boxplot_stats (claves leidas con .get: q1, median, q3, whisker_lo, whisker_hi, min, max, has_low_outliers, has_high_outliers, lower_fence, upper_fence, n_outliers). fliers es la lista opcional de outliers crudos: si viene se dibuja como puntos; si es None/ausente solo se marcan los extremos box[min]/box[max] cuando hay outliers de cola. Entradas que no son dict, sin box dict, o sin q1/median/q3 se omiten. El caller las pasa ya ordenadas por contaminacion (la mayor primera)."
+  - name: title
+    desc: "Titulo de la figura (fig.suptitle, alineado a la izquierda). Vacio => sin titulo. Si len(boxes) > max_boxes se le anade una nota \"(mostrando N de M)\" para que la truncacion no sea silenciosa. Default \"\"."
+  - name: max_boxes
+    desc: "Numero maximo de cajas a dibujar (las primeras de la lista). Default 12. Un valor no entero o <= 0 cae a 12. Si la lista trae mas entradas, las sobrantes se descartan pero se reporta en el titulo con (mostrando N de M)."
+output: "Un matplotlib.figure.Figure (figsize 7.0 x alto adaptativo = max(2.0, 0.5*n + 1.0), dpi 150) con un unico Axes que apila boxplots horizontales de Tukey (ax.bxp, orientation=horizontal con fallback vert=False), uno por columna valida, de arriba a abajo en el orden recibido. Cada caja: relleno #9ec6df, borde/bigotes/caps #5b8aa6, mediana #2e8b57, atipicos #c0392b. Etiquetas del eje Y = nombres de columna; eje X etiquetado \"valor\". Outliers dibujados desde fliers crudos (showfliers) o, si faltan, marcados en box[min]/box[max] segun has_low/high_outliers. Si no queda ninguna caja valida (lista vacia o todas invalidas) devuelve una Figure placeholder con texto centrado \"(sin boxplots)\"; cualquier error inesperado se captura y devuelve una Figure con el mensaje de error. NUNCA lanza. El caller rasteriza/cierra la figura; la funcion no la muestra ni la guarda."
+---
+
+## Ejemplo
+
+```python
+import sys, os
+sys.path.insert(0, os.path.join("python", "functions"))
+from datascience.build_boxplot_stats import build_boxplot_stats
+from datascience.build_boxplots_figure import build_boxplots_figure
+
+# Un `box` por columna numérica, derivado del sub-bloque `numeric` del profile
+# (salida de describe_numeric). El caller los pasa ya ordenados por outlier_pct.
+boxes = [
+    {
+        "name": "ingresos",
+        "box": build_boxplot_stats({
+            "min": 1.0, "max": 9000.0,
+            "p25": 1000.0, "median": 2000.0, "p75": 3000.0,
+            "n_outliers": 7,
+        }),
+        "fliers": None,  # valores crudos desconocidos -> se marca solo el extremo.
+    },
+    {
+        "name": "edad",
+        "box": build_boxplot_stats({
+            "min": 0.0, "max": 99.0,
+            "p25": 25.0, "median": 38.0, "p75": 52.0,
+        }),
+        "fliers": [88.0, 95.0, 99.0],  # outliers crudos -> se dibujan como puntos.
+    },
+]
+
+fig = build_boxplots_figure(boxes, title="Outliers por columna", max_boxes=12)
+
+# El renderer del informe lo rasteriza; aquí solo persistimos para inspección.
+fig.savefig("/tmp/boxplots.png")
+```
+
+## Cuando usarla
+
+Úsala en el capítulo de outliers de un informe EDA cuando quieras comparar de un
+vistazo *qué columnas están más contaminadas por valores atípicos*: a diferencia
+de `num_distr` (que dibuja un histograma+boxplot por columna en figuras
+separadas), aquí apilas todos los boxplots horizontales en **una sola figura**
+(small multiples). Primero deriva el `box` de cada columna con
+`build_boxplot_stats`, ordénalas por `outlier_pct` descendente, envuélvelas como
+`{"name", "box", "fliers"}` y pásaselas. Si tienes los valores crudos fuera de
+las vallas, métele la lista `fliers` y se dibujarán como puntos; si no, la
+función marca solo los extremos `min`/`max` cuando hay cola.
+
+## Gotchas
+
+- **Impura por matplotlib.** Toca la maquinaria de render. Usa el backend `Agg`
+  y la API orientada a objetos `Figure`/`add_subplot` — NUNCA `pyplot.*` aquí,
+  para no tocar el estado global ni filtrar figuras entre llamadas. `pyplot` NO
+  es thread-safe; esta función construye el `Figure` directamente, así que es
+  segura de llamar en bucle desde el renderer.
+- **El caller cierra la figura.** Devuelve el `Figure` pero no lo muestra ni lo
+  guarda. Quien la consume debe rasterizarla y luego liberarla
+  (`matplotlib.pyplot.close(fig)`) para no acumular memoria en lotes grandes.
+- **`fliers` opcional, semántica distinta.** Si pasas la lista de outliers
+  crudos se dibujan todos como puntos (`showfliers=True`). Si es `None`/ausente
+  los valores son desconocidos y solo se marca un punto en `box["min"]` /
+  `box["max"]` cuando `has_low_outliers` / `has_high_outliers` — mismo criterio
+  que `num_distr`. No inventes fliers a partir del profile: el `box` no trae los
+  valores crudos, solo si los extremos superan las vallas.
+- **API de orientación de `ax.bxp`.** matplotlib reciente usa
+  `orientation="horizontal"`; las versiones antiguas usan `vert=False`. La
+  función prueba la primera y cae a la segunda en `except TypeError`, así que
+  funciona en ambas. Si `bxp` falla del todo, el Axes degrada a un texto
+  "(boxplot no disponible)" en vez de propagar.
+- **Truncación visible.** `max_boxes` (default 12) limita el nº de cajas para que
+  ninguna se solape; si la lista trae más, las sobrantes se descartan pero se
+  avisa en el título con "(mostrando N de M)". Pasa las columnas ya ordenadas por
+  contaminación para que las descartadas sean las menos relevantes.
+- **Defensiva, nunca lanza.** Lista vacía, entradas no-dict, sin `box`, o sin
+  `q1`/`median`/`q3` se omiten sin propagar; sin cajas válidas devuelve un
+  placeholder "(sin boxplots)" y cualquier error inesperado se captura en una
+  figura con el texto del error. No envuelvas la llamada en try/except por miedo
+  a un raise — no lo hay.

python/functions/datascience/build_boxplots_figure.py

@@ -0,0 +1,250 @@
+"""Impure EDA helper: a single figure of horizontal Tukey boxplots (`eda` group).
+
+Draws, in one ``matplotlib.figure.Figure``, a stack of horizontal Tukey boxplots
+(one per column) using ``ax.bxp``: each carries its box (Q1–Q3), whiskers (up to
+1.5·IQR), the median line and its outlier points. It consumes the output of the
+pure registry function ``build_boxplot_stats`` (one ``box`` dict per column) plus
+an optional list of raw outlier values per column; it never recomputes anything.
+
+It is the "small-multiples" companion of ``num_distr`` (which draws one
+histogram+boxplot per column): here every column shares a single figure so the
+caller can show, at a glance, *which* columns are the most contaminated by
+outliers (the caller passes them already ordered by contamination).
+
+Impure because it touches matplotlib's rendering machinery. It uses the headless
+Agg backend and the object-oriented ``Figure`` API (no ``pyplot``) so it leaks no
+global state and is safe to call repeatedly from a report renderer. It is fully
+defensive and NEVER raises: invalid entries are skipped and, if nothing valid
+remains, it returns a placeholder figure carrying a centered "(sin boxplots)".
+"""
+
+import matplotlib
+
+matplotlib.use("Agg")
+
+from matplotlib.figure import Figure  # noqa: E402
+
+# Blue palette shared with the ``num_distr`` chapter so the report stays coherent.
+_BOX_FACE = "#9ec6df"   # box fill.
+_BOX_EDGE = "#5b8aa6"   # box / whisker / cap border.
+_MEDIAN = "#2e8b57"     # median line (sea green).
+_OUTLIER = "#c0392b"    # outlier points (soft red).
+# Muted gray for the placeholder / fallback message text.
+_MUTED_TEXT = "#5f6b7a"
+# Soft red for the error fallback message.
+_ERROR_TEXT = "#b00020"
+
+
+def _num(value):
+    """Coerce ``value`` to float defensively; None for None/bool/non-numeric/NaN."""
+    # bool is a subclass of int; a stat value is never a real bool, so treat
+    # True/False as missing instead of silently coercing to 1.0/0.0.
+    if value is None or isinstance(value, bool):
+        return None
+    try:
+        f = float(value)
+    except (TypeError, ValueError):
+        return None
+    if f != f:  # NaN guard.
+        return None
+    return f
+
+
+def _placeholder_figure(message: str, color: str = _MUTED_TEXT) -> "Figure":
+    """Return a fallback ``Figure`` carrying a single centered message."""
+    fig = Figure(figsize=(7.0, 2.4), dpi=150)
+    ax = fig.add_subplot(111)
+    ax.axis("off")
+    ax.text(
+        0.5,
+        0.5,
+        message,
+        ha="center",
+        va="center",
+        fontsize=12,
+        color=color,
+        wrap=True,
+        transform=ax.transAxes,
+    )
+    fig.tight_layout()
+    return fig
+
+
+def build_boxplots_figure(
+    boxes: list,
+    title: str = "",
+    max_boxes: int = 12,
+) -> "matplotlib.figure.Figure":
+    """Build one figure of stacked horizontal Tukey boxplots (one per column).
+
+    For each entry the function builds a ``bxp`` stats record (``med, q1, q3,
+    whislo, whishi, fliers, label``) from its ``box`` sub-dict (the output of
+    ``build_boxplot_stats``) and draws all of them as horizontal boxplots sharing
+    the X axis, top-to-bottom in the order received (the caller is expected to
+    pass them already sorted by contamination).
+
+    Outliers are shown two ways:
+
+    - If an entry carries a ``fliers`` list (the raw out-of-fence values), they
+      are drawn as red points via ``ax.bxp(..., showfliers=True)``.
+    - If ``fliers`` is ``None``/absent, the raw values are unknown, so only the
+      extremes are marked: a red point at ``box["min"]`` when
+      ``box["has_low_outliers"]`` and at ``box["max"]`` when
+      ``box["has_high_outliers"]`` (same convention as ``num_distr``).
+
+    The function is fully defensive and NEVER raises. Entries that are not dicts,
+    lack a ``box`` dict, or miss any of ``q1``/``median``/``q3`` are skipped. If
+    after filtering no valid box remains it returns a placeholder ``Figure`` with
+    a centered "(sin boxplots)"; any unexpected error is caught and turned into a
+    fallback figure carrying the error text. It always returns a ``Figure``.
+
+    Args:
+        boxes: List of dicts ``{"name": str, "box": dict, "fliers": list|None}``.
+            ``box`` is exactly the output of ``build_boxplot_stats`` (read with
+            ``.get``: ``q1, median, q3, whisker_lo, whisker_hi, min, max,
+            has_low_outliers, has_high_outliers, ...``). ``fliers`` is the
+            optional list of raw outlier values; when present they are plotted,
+            otherwise only the extremes are marked.
+        title: Figure title (``fig.suptitle``). Empty => no title. When the list
+            is longer than ``max_boxes`` a "(mostrando N de M)" note is appended.
+        max_boxes: Draw at most the first ``max_boxes`` entries (default 12). The
+            rest are dropped but their omission is surfaced in the title note, so
+            the truncation is never silent.
+
+    Returns:
+        A ``matplotlib.figure.Figure`` with a single Axes holding the horizontal
+        boxplots (height adaptive to the box count so none overlap). The caller is
+        responsible for rasterizing/closing it; this function never shows nor
+        saves it.
+    """
+    try:
+        if not isinstance(boxes, (list, tuple)) or len(boxes) == 0:
+            return _placeholder_figure("(sin boxplots)")
+
+        total = len(boxes)
+
+        # Cap the number of boxes; tolerate a non-int / non-positive max_boxes.
+        try:
+            cap = int(max_boxes)
+        except (TypeError, ValueError):
+            cap = 12
+        if cap <= 0:
+            cap = 12
+        candidates = list(boxes)[:cap]
+
+        stats_list = []        # bxp stats records, in draw order.
+        labels = []            # Y tick labels (column names).
+        manual_markers = []    # (position, box) for entries without raw fliers.
+        any_fliers = False     # whether to enable showfliers in the bxp call.
+
+        for entry in candidates:
+            if not isinstance(entry, dict):
+                continue
+            box = entry.get("box")
+            if not isinstance(box, dict):
+                continue
+
+            q1 = _num(box.get("q1"))
+            med = _num(box.get("median"))
+            q3 = _num(box.get("q3"))
+            # Without the three quartiles a boxplot cannot be drawn — skip it.
+            if q1 is None or med is None or q3 is None:
+                continue
+
+            # Whisker extremes fall back to the quartiles when missing.
+            whislo = _num(box.get("whisker_lo"))
+            whishi = _num(box.get("whisker_hi"))
+            if whislo is None:
+                whislo = q1
+            if whishi is None:
+                whishi = q3
+
+            name = entry.get("name")
+            label = "" if name is None else str(name)
+
+            position = len(stats_list) + 1  # bxp positions are 1-indexed.
+            fliers_raw = entry.get("fliers")
+            if isinstance(fliers_raw, (list, tuple)):
+                fliers = [v for v in (_num(x) for x in fliers_raw) if v is not None]
+                if fliers:
+                    any_fliers = True
+            else:
+                # Raw values unknown: draw no bxp fliers, mark min/max by hand.
+                fliers = []
+                manual_markers.append((position, box))
+
+            stats_list.append({
+                "med": med,
+                "q1": q1,
+                "q3": q3,
+                "whislo": whislo,
+                "whishi": whishi,
+                "fliers": fliers,
+                "label": label,
+            })
+            labels.append(label)
+
+        if not stats_list:
+            return _placeholder_figure("(sin boxplots)")
+
+        n = len(stats_list)
+        positions = list(range(1, n + 1))
+
+        # Height grows with the box count so none of them overlap.
+        height = max(2.0, 0.5 * n + 1.0)
+        fig = Figure(figsize=(7.0, height), dpi=150)
+        ax = fig.add_subplot(111)
+
+        bxp_kw = dict(
+            showfliers=any_fliers, widths=0.5, patch_artist=True,
+            boxprops={"facecolor": _BOX_FACE, "edgecolor": _BOX_EDGE},
+            medianprops={"color": _MEDIAN, "linewidth": 1.6},
+            whiskerprops={"color": _BOX_EDGE},
+            capprops={"color": _BOX_EDGE},
+            flierprops={"marker": "o", "markersize": 3.5,
+                        "markerfacecolor": _OUTLIER, "markeredgecolor": _OUTLIER,
+                        "linestyle": "none"})
+        try:
+            # ``orientation`` is the current API; older matplotlib uses ``vert``.
+            try:
+                ax.bxp(stats_list, positions=positions,
+                       orientation="horizontal", **bxp_kw)
+            except TypeError:
+                ax.bxp(stats_list, positions=positions, vert=False, **bxp_kw)
+        except Exception:  # noqa: BLE001 — never let bxp kill the whole figure.
+            ax.text(0.5, 0.5, "(boxplot no disponible)", ha="center",
+                    va="center", fontsize=10, color=_MUTED_TEXT,
+                    transform=ax.transAxes)
+
+        # For entries without raw fliers, mark only the out-of-fence extremes.
+        for position, box in manual_markers:
+            mn = _num(box.get("min"))
+            mx = _num(box.get("max"))
+            if box.get("has_low_outliers") and mn is not None:
+                ax.plot([mn], [position], marker="o", markersize=3.5,
+                        color=_OUTLIER, zorder=5)
+            if box.get("has_high_outliers") and mx is not None:
+                ax.plot([mx], [position], marker="o", markersize=3.5,
+                        color=_OUTLIER, zorder=5)
+
+        # Pin the Y tick labels explicitly so they work across matplotlib
+        # versions regardless of whether ``bxp`` consumed the ``label`` key.
+        ax.set_yticks(positions)
+        ax.set_yticklabels(labels, fontsize=8)
+        ax.set_xlabel("valor", fontsize=9)
+        ax.tick_params(labelsize=7)
+        ax.margins(y=0.15)
+        for spine in ("top", "right"):
+            ax.spines[spine].set_visible(False)
+
+        # Surface truncation in the title instead of silently dropping boxes.
+        note = f"(mostrando {n} de {total})" if total > cap else ""
+        heading = "  ".join(p for p in (title, note) if p)
+        if heading:
+            fig.suptitle(heading, fontsize=12, x=0.02, ha="left")
+
+        fig.tight_layout()
+        return fig
+    except Exception as exc:  # noqa: BLE001 — never raise from a figure builder.
+        return _placeholder_figure(
+            f"error al dibujar boxplots: {exc}", color=_ERROR_TEXT)

python/functions/datascience/build_boxplots_figure_test.py

@@ -0,0 +1,109 @@
+"""Tests para build_boxplots_figure (boxplots horizontales de Tukey, grupo eda).
+
+Usa el backend Agg sin display; no muestra ni guarda figuras. Cada test cierra
+explícitamente la Figure construida (matplotlib.pyplot.close) para no acumular
+estado entre tests.
+"""
+
+import matplotlib
+
+matplotlib.use("Agg")
+
+import matplotlib.pyplot as plt  # noqa: E402
+from matplotlib.figure import Figure  # noqa: E402
+
+from build_boxplots_figure import build_boxplots_figure
+
+
+def _box(name, q1, median, q3, mn, mx, low=False, high=False, fliers=None):
+    """Construye una entrada {name, box, fliers} con un box estilo build_boxplot_stats."""
+    iqr = q3 - q1
+    return {
+        "name": name,
+        "box": {
+            "q1": q1,
+            "median": median,
+            "q3": q3,
+            "iqr": iqr,
+            "lower_fence": q1 - 1.5 * iqr,
+            "upper_fence": q3 + 1.5 * iqr,
+            "whisker_lo": max(mn, q1 - 1.5 * iqr),
+            "whisker_hi": min(mx, q3 + 1.5 * iqr),
+            "min": mn,
+            "max": mx,
+            "has_low_outliers": low,
+            "has_high_outliers": high,
+            "n_outliers": 0,
+        },
+        "fliers": fliers,
+    }
+
+
+def test_returns_figure_with_axes():
+    boxes = [
+        _box("edad", 10.0, 25.0, 40.0, 1.0, 100.0, high=True),
+        _box("ingresos", 100.0, 200.0, 300.0, 50.0, 400.0),
+        _box("score", -1.0, 0.0, 1.0, -5.0, 5.0, low=True, high=True),
+    ]
+    fig = build_boxplots_figure(boxes, title="Boxplots", max_boxes=12)
+    assert isinstance(fig, Figure)
+    assert len(fig.axes) >= 1
+    # Tres cajas -> tres etiquetas en el eje Y.
+    ax = fig.axes[0]
+    assert len(ax.get_yticks()) == 3
+    plt.close(fig)
+
+
+def test_empty_list_returns_placeholder_figure():
+    fig = build_boxplots_figure([], title="vacío")
+    assert isinstance(fig, Figure)
+    assert len(fig.axes) >= 1
+    plt.close(fig)
+
+
+def test_invalid_box_is_skipped_not_raised():
+    boxes = [
+        {"name": "rota", "box": {"q1": None, "median": None, "q3": None}},
+        {"name": "sin_box"},                         # falta la clave box.
+        "no_es_dict",                                 # entrada no-dict.
+        _box("buena", 1.0, 2.0, 3.0, 0.0, 10.0, high=True),
+    ]
+    fig = build_boxplots_figure(boxes)
+    assert isinstance(fig, Figure)
+    ax = fig.axes[0]
+    # Solo la caja válida sobrevive al filtrado.
+    assert len(ax.get_yticks()) == 1
+    plt.close(fig)
+
+
+def test_all_invalid_returns_placeholder():
+    boxes = [
+        {"name": "a", "box": {"q1": None, "median": 1.0, "q3": 2.0}},
+        {"name": "b"},
+    ]
+    fig = build_boxplots_figure(boxes)
+    assert isinstance(fig, Figure)
+    assert len(fig.axes) >= 1
+    plt.close(fig)
+
+
+def test_raw_fliers_are_drawn():
+    boxes = [
+        _box("con_fliers", 10.0, 20.0, 30.0, 5.0, 200.0,
+             high=True, fliers=[150.0, 180.0, 200.0]),
+    ]
+    fig = build_boxplots_figure(boxes)
+    assert isinstance(fig, Figure)
+    assert len(fig.axes) >= 1
+    plt.close(fig)
+
+
+def test_max_boxes_truncates_and_does_not_raise():
+    boxes = [_box(f"c{i}", float(i), float(i + 1), float(i + 2),
+                  float(i - 5), float(i + 10)) for i in range(20)]
+    fig = build_boxplots_figure(boxes, title="muchos", max_boxes=5)
+    assert isinstance(fig, Figure)
+    ax = fig.axes[0]
+    # Solo se dibujan las primeras 5 cajas.
+    assert len(ax.get_yticks()) == 5
+    plt.close(fig)

python/functions/datascience/classify_relationship_type.md

@@ -0,0 +1,68 @@
+---
+name: classify_relationship_type
+kind: function
+lang: py
+domain: datascience
+version: "1.0.0"
+purity: pure
+signature: "def classify_relationship_type(xs: list, ys: list) -> dict"
+description: "Clasifica el TIPO de relacion entre dos variables numericas pareadas por indice para el EDA automatico del grupo eda. Limpia los pares de forma defensiva (descarta None/bool/NaN/inf), reusa pearson y spearman_corr del registry y ajusta polinomios de grado 2 y 3 con numpy.polyfit (R^2 manual), y a partir de esas senales etiqueta la forma: 'lineal', 'polinomica (grado 2/3)', 'monotona no-lineal' o 'debil/sin forma'. Orden de decision: debil -> monotona -> polinomica -> lineal (la primera que matchea gana), con umbrales calibrados para datos reales discretos/ruidosos. Devuelve ademas los coeficientes del mejor modelo en orden de numpy.polyval para pintar la curva de ajuste sobre el scatter. Funcion pura no-throw: ante datos insuficientes (menos de 5 pares validos o varianza ~0) o cualquier fallo devuelve el dict canonico con tipo='debil/sin forma' y el resto a None."
+tags: [eda, correlation, relationship, classification, polyfit, datascience, pure]
+params:
+  - name: xs
+    desc: "Lista (o tupla) de valores numericos de la primera variable, pareada por indice con ys. Cada par xs[i],ys[i] se descarta si cualquiera de los dos es None, bool, NaN o inf. Lectura defensiva."
+  - name: ys
+    desc: "Lista (o tupla) de valores numericos de la segunda variable, pareada por indice con xs. Mismas reglas de limpieza que xs."
+output: "Dict con SIEMPRE las mismas 8 claves: tipo (str: 'lineal' | 'polinómica (grado 2)' | 'polinómica (grado 3)' | 'monótona no-lineal' | 'débil/sin forma'); pearson (float|None: coeficiente de Pearson r); r2_linear (float|None: r**2 del ajuste lineal); spearman (float|None: rho de Spearman); r2_poly2 (float|None: R^2 del ajuste polinomico de grado 2); r2_poly3 (float|None: R^2 del ajuste de grado 3); best_degree (int|None: grado del modelo elegido — 1 lineal, 2/3 polinomico, None si monotona/debil); coeffs (list|None: coeficientes del mejor modelo en orden de numpy.polyval para pintar la curva, o None). Ante datos insuficientes o error: tipo='débil/sin forma' y el resto de claves a None."
+uses_functions: [pearson_py_datascience, spearman_corr_py_datascience]
+uses_types: []
+returns: []
+returns_optional: false
+error_type: ""
+imports: [numpy]
+tested: true
+tests: ["test_lineal", "test_polinomica_cuadratica", "test_monotona_no_lineal", "test_monotona_exponencial", "test_debil_sin_forma", "test_lista_vacia_no_lanza", "test_longitudes_distintas_no_lanza", "test_todos_none_no_lanza", "test_entradas_none_no_lanza", "test_constante_no_lanza", "test_filtra_nan_inf_bool"]
+test_file_path: "python/functions/datascience/classify_relationship_type_test.py"
+file_path: "python/functions/datascience/classify_relationship_type.py"
+---
+
+## Ejemplo
+
+```python
+import sys, os
+sys.path.insert(0, os.path.join("python", "functions"))
+from datascience.classify_relationship_type import classify_relationship_type
+import numpy as np
+
+# Relacion claramente cuadratica (forma de parabola) sobre dominio simetrico.
+x = list(np.linspace(-10, 10, 60))
+y = [v * v for v in x]
+
+res = classify_relationship_type(x, y)
+print(res["tipo"])         # 'polinómica (grado 2)'
+print(res["best_degree"])  # 2
+print(res["r2_linear"])    # 0.0   -> el Pearson lineal no ve la parabola
+print(res["r2_poly2"])     # 1.0
+print(res["coeffs"])       # [1.0, -0.0, -0.0]  -> numpy.polyval(coeffs, x) ~ x**2
+
+# El capitulo pinta la curva de ajuste cuando coeffs no es None:
+#   if res["coeffs"] is not None:
+#       xs_fit = np.linspace(min(x), max(x), 200)
+#       ys_fit = np.polyval(res["coeffs"], xs_fit)
+#       ax.plot(xs_fit, ys_fit)   # curva sobre el ax.scatter(x, y)
+```
+
+## Cuando usarla
+
+- Usala en el capitulo de relaciones/correlaciones del EDA automatico, despues de detectar dos columnas numericas con alguna asociacion, para decidir QUE curva de ajuste pintar sobre el scatter (recta, parabola, cubica o ninguna) y poner una etiqueta legible al tipo de relacion.
+- Cuando un Pearson bajo no signifique "sin relacion": esta funcion cruza Pearson con Spearman y con ajustes polinomicos para distinguir una relacion lineal debil de una monotona no-lineal (que el rango si capta) o de una curva polinomica.
+- Cuando necesites un punto de entrada determinista y no-throw que, con los mismos datos, devuelva siempre el mismo `tipo` y los mismos `coeffs` listos para `numpy.polyval` sin tener que ajustar modelos a mano en el capitulo.
+
+## Gotchas
+
+- Funcion pura, deterministica y no-throw: ante menos de 5 pares validos, varianza ~0 (xs o ys constante) o cualquier excepcion interna devuelve el dict canonico `tipo="débil/sin forma"` con el resto de claves a `None`. El dict SIEMPRE trae las 8 claves: nunca compruebes existencia, comprueba `None`.
+- El orden de decision importa: `débil -> monótona -> polinómica -> lineal` (la primera que matchee gana). La monotonia se evalua ANTES que el ajuste polinomico, asi que una curva monotona suave (exp, log, potencias) sale `monótona no-lineal` aunque un cubico tambien la ajuste — la dominancia del rango (Spearman >> Pearson) es la senal mas interpretable. Solo cae en `polinómica` una forma curva NO monotona (p.ej. una parabola, Spearman ~0 pero R^2 polinomico alto).
+- Umbrales fijos (calibrados para EDA con datos discretos/ruidosos, no para inferencia formal): `débil/sin forma` si las tres senales son bajas a la vez (`abs(pearson) < 0.3` y `abs(spearman) < 0.3` y `mejor_poly < 0.3`); `monótona no-lineal` si `abs(spearman) - abs(pearson) >= 0.1` y `abs(spearman) >= 0.4`; `polinómica (grado N)` si el mejor polinomico mejora `>= 0.1` sobre el lineal y su R^2 `>= 0.3`; en cualquier otro caso con senal (no debil) `lineal`. El suelo de 0.3 evita llamar "debil" a relaciones reales pero discretas (conteos, escalas ordinales) con R^2 bajo pero direccion clara.
+- `coeffs` va en orden de `numpy.polyval` (grado descendente). Para `lineal` es `[pendiente, intercepto]` (grado 1); para `polinómica` los del grado elegido; para `monótona no-lineal` y `débil/sin forma` es `None` (el scatter pintara una curva suavizada o nada — lo decide el capitulo, no esta funcion).
+- `best_degree` prefiere el grado 2 sobre el 3 cuando empatan dentro de 0.02 de R^2 (parsimonia): no esperes grado 3 salvo que mejore claramente.
+- Los pares con `None`, `bool`, `NaN` o `inf` se descartan por indice en silencio; `bool` cuenta como no-numerico (un `True` no es `1`). El dominio de los datos afecta al resultado: una parabola sobre un dominio simetrico da Pearson ~0 (sale `polinómica`), pero sobre un dominio asimetrico el Pearson sube y puede salir `lineal`.

python/functions/datascience/classify_relationship_type.py

@@ -0,0 +1,187 @@
+"""Clasifica el TIPO de relacion entre dos variables numericas pareadas.
+
+Funcion pura del grupo eda. Dadas dos listas numericas pareadas por indice,
+limpia los pares de forma defensiva, calcula correlaciones lineal (Pearson) y de
+rangos (Spearman) y ajustes polinomicos de grado 2 y 3, y a partir de esas
+senales etiqueta la forma de la relacion para el EDA automatico:
+
+    "lineal" | "polinómica (grado 2)" | "polinómica (grado 3)" |
+    "monótona no-lineal" | "débil/sin forma"
+
+Ademas devuelve los coeficientes del mejor modelo (en orden de numpy.polyval)
+para que el capitulo pinte la curva de ajuste sobre el scatter. Reusa las
+funciones del registry `pearson` y `spearman_corr` en vez de reimplementarlas.
+
+NUNCA lanza: ante cualquier fallo o dato insuficiente devuelve el dict canonico
+con tipo="débil/sin forma" y el resto de claves a None.
+"""
+
+import math
+import warnings
+
+import numpy as np
+
+from datascience.datascience import pearson
+from datascience.spearman_corr import spearman_corr
+
+# Forma canonica de la respuesta cuando no se puede clasificar (datos
+# insuficientes, varianza nula o error interno). Siempre las mismas claves.
+_WEAK = {
+    "tipo": "débil/sin forma",
+    "pearson": None,
+    "r2_linear": None,
+    "spearman": None,
+    "r2_poly2": None,
+    "r2_poly3": None,
+    "best_degree": None,
+    "coeffs": None,
+}
+
+
+def _is_num(v) -> bool:
+    """True si v es un numero real finito (int/float, no bool, no NaN, no inf)."""
+    return (
+        isinstance(v, (int, float))
+        and not isinstance(v, bool)
+        and not (isinstance(v, float) and (math.isnan(v) or math.isinf(v)))
+    )
+
+
+def _poly_r2(coeffs, x_arr, y_arr, ss_tot: float) -> float:
+    """R^2 de un ajuste polinomico: 1 - SS_res/SS_tot. 0 si SS_tot==0."""
+    if ss_tot == 0.0:
+        return 0.0
+    pred = np.polyval(coeffs, x_arr)
+    ss_res = float(np.sum((y_arr - pred) ** 2))
+    return 1.0 - ss_res / ss_tot
+
+
+def classify_relationship_type(xs: list, ys: list) -> dict:
+    """Clasifica el tipo de relacion entre dos variables numericas pareadas.
+
+    Empareja xs[i],ys[i] por indice y descarta el par si cualquiera de los dos
+    es None, bool, NaN o inf. Sobre los pares limpios calcula Pearson r
+    (r2_linear = r**2), Spearman rho y los R^2 de ajustes polinomicos de grado 2
+    y 3 (con numpy.polyfit + R^2 manual). Con esas senales decide la etiqueta.
+
+    Orden de evaluacion de la etiqueta (la primera que matchee gana). Los
+    umbrales estan calibrados para datos reales, a menudo discretos y ruidosos
+    (conteos, escalas ordinales): una relacion con |r| >= 0.3, |rho| >= 0.3 o un
+    polinomio con R^2 >= 0.3 ya tiene FORMA y no debe etiquetarse como "debil".
+        1. "débil/sin forma" — todas las senales bajas a la vez:
+           abs(pearson) < 0.3 y abs(spearman) < 0.3 y mejor_poly < 0.3.
+        2. "monótona no-lineal" — el rango (Spearman) capta una monotonia que el
+           Pearson lineal no: abs(spearman) - abs(pearson) >= 0.1 y
+           abs(spearman) >= 0.4. No se fuerza un polinomio (coeffs/best_degree =
+           None); el capitulo dibuja la tendencia ordenada sobre el scatter.
+        3. "polinómica (grado N)" — el mejor polinomico mejora claramente sobre
+           el lineal (mejor_poly - r2_linear >= 0.1) y mejor_poly >= 0.3. N es el
+           grado (2 o 3) con mejor R^2, prefiriendo el 2 si empatan dentro de 0.02
+           (parsimonia).
+        4. "lineal" — el resto: hay senal (no es debil) y la forma que existe es
+           esencialmente lineal. best_degree=1, coeffs del ajuste de grado 1.
+
+    Si hay menos de 5 pares validos, o la varianza de xs o de ys es ~0
+    (constante), devuelve directamente "débil/sin forma".
+
+    Args:
+        xs: lista (o tupla) de valores numericos de la primera variable,
+            pareada por indice con ys. Pares con None/bool/NaN/inf se descartan.
+        ys: lista (o tupla) de valores numericos de la segunda variable,
+            pareada por indice con xs.
+
+    Returns:
+        dict con SIEMPRE las mismas claves:
+            tipo (str), pearson (float|None), r2_linear (float|None),
+            spearman (float|None), r2_poly2 (float|None), r2_poly3 (float|None),
+            best_degree (int|None: 1, 2, 3 o None),
+            coeffs (list|None: coeficientes en orden de numpy.polyval, o None).
+        Nunca lanza: ante fallo o datos insuficientes devuelve el dict debil.
+    """
+    try:
+        if xs is None or ys is None:
+            return dict(_WEAK)
+
+        pairs = [
+            (float(x), float(y))
+            for x, y in zip(xs, ys)
+            if _is_num(x) and _is_num(y)
+        ]
+
+        # Datos insuficientes para hablar de forma de la relacion.
+        if len(pairs) < 5:
+            return dict(_WEAK)
+
+        clean_x = [p[0] for p in pairs]
+        clean_y = [p[1] for p in pairs]
+
+        # Varianza ~0 en cualquiera de las series => relacion indefinida.
+        if len(set(clean_x)) < 2 or len(set(clean_y)) < 2:
+            return dict(_WEAK)
+        x_arr = np.asarray(clean_x, dtype=float)
+        y_arr = np.asarray(clean_y, dtype=float)
+        if float(np.var(x_arr)) < 1e-15 or float(np.var(y_arr)) < 1e-15:
+            return dict(_WEAK)
+
+        # Correlaciones reutilizando las funciones del registry.
+        r = pearson(clean_x, clean_y)
+        spearman = spearman_corr(clean_x, clean_y)
+        r2_linear = r ** 2
+
+        # Ajustes polinomicos grado 2 y 3 con R^2 manual.
+        ss_tot = float(np.sum((y_arr - float(np.mean(y_arr))) ** 2))
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore")
+            c1 = np.polyfit(x_arr, y_arr, 1)
+            c2 = np.polyfit(x_arr, y_arr, 2)
+            c3 = np.polyfit(x_arr, y_arr, 3)
+        r2_poly2 = _poly_r2(c2, x_arr, y_arr, ss_tot)
+        r2_poly3 = _poly_r2(c3, x_arr, y_arr, ss_tot)
+
+        mejor_poly = max(r2_poly2, r2_poly3)
+        # Grado del mejor polinomico, con preferencia por la parsimonia: solo se
+        # elige el grado 3 si supera al grado 2 por mas de 0.02.
+        best_poly_degree = 3 if (r2_poly3 - r2_poly2) > 0.02 else 2
+
+        abs_s = abs(spearman)
+        abs_p = abs(r)
+
+        # Decision en orden: debil-temprano -> monotona -> polinomica -> lineal.
+        if abs_p < 0.3 and abs_s < 0.3 and mejor_poly < 0.3:
+            # Ninguna senal supera el suelo de forma: relacion debil/sin forma.
+            tipo = "débil/sin forma"
+            best_degree = None
+            coeffs = None
+        elif (abs_s - abs_p) >= 0.1 and abs_s >= 0.4:
+            # Spearman (rango) capta una monotonia que el Pearson lineal no:
+            # relacion monotona no-lineal. No se fuerza un polinomio que tal vez
+            # no ajusta bien; el capitulo dibuja la tendencia ordenada.
+            tipo = "monótona no-lineal"
+            best_degree = None
+            coeffs = None
+        elif (mejor_poly - r2_linear) >= 0.1 and mejor_poly >= 0.3:
+            tipo = "polinómica (grado {})".format(best_poly_degree)
+            best_degree = best_poly_degree
+            best_coeffs = c2 if best_poly_degree == 2 else c3
+            coeffs = [float(c) for c in best_coeffs]
+        else:
+            # Hay senal (no es debil) y no es ni monotona-pura ni polinomica:
+            # la correlacion que existe es esencialmente lineal.
+            tipo = "lineal"
+            best_degree = 1
+            coeffs = [float(c) for c in c1]
+
+        return {
+            "tipo": tipo,
+            "pearson": round(float(r), 6),
+            "r2_linear": round(float(r2_linear), 6),
+            "spearman": round(float(spearman), 6),
+            "r2_poly2": round(float(r2_poly2), 6),
+            "r2_poly3": round(float(r2_poly3), 6),
+            "best_degree": best_degree,
+            "coeffs": (
+                [round(c, 8) for c in coeffs] if coeffs is not None else None
+            ),
+        }
+    except Exception:
+        return dict(_WEAK)

python/functions/datascience/classify_relationship_type_test.py

@@ -0,0 +1,174 @@
+"""Tests para classify_relationship_type."""
+
+import os
+import sys
+
+import numpy as np
+
+sys.path.insert(0, os.path.dirname(__file__))
+
+from classify_relationship_type import classify_relationship_type
+
+# Claves que el dict de salida debe contener SIEMPRE.
+_EXPECTED_KEYS = {
+    "tipo", "pearson", "r2_linear", "spearman",
+    "r2_poly2", "r2_poly3", "best_degree", "coeffs",
+}
+
+
+def _assert_shape(r):
+    """Toda salida tiene exactamente las 8 claves canonicas."""
+    assert isinstance(r, dict)
+    assert set(r.keys()) == _EXPECTED_KEYS
+
+
+def test_lineal():
+    """Golden: y = 2x + 1 con ruido pequeno -> 'lineal', best_degree=1."""
+    rng = np.random.default_rng(42)
+    x = np.linspace(0.0, 10.0, 50)
+    y = 2.0 * x + 1.0 + rng.normal(0.0, 0.3, 50)
+
+    r = classify_relationship_type(list(x), list(y))
+    _assert_shape(r)
+
+    assert r["tipo"] == "lineal"
+    assert r["best_degree"] == 1
+    assert r["r2_linear"] >= 0.5
+    # coeffs ~ [pendiente, intercepto] del ajuste de grado 1.
+    assert r["coeffs"] is not None and len(r["coeffs"]) == 2
+    assert abs(r["coeffs"][0] - 2.0) < 0.1   # pendiente ~2
+    assert abs(r["coeffs"][1] - 1.0) < 0.3   # intercepto ~1
+
+
+def test_polinomica_cuadratica():
+    """Golden: y = x**2 sobre [-10, 10] -> 'polinómica', best_degree in (2, 3)."""
+    x = np.linspace(-10.0, 10.0, 60)
+    y = x ** 2
+
+    r = classify_relationship_type(list(x), list(y))
+    _assert_shape(r)
+
+    assert r["tipo"].startswith("polinómica")
+    assert r["best_degree"] in (2, 3)
+    # Una parabola perfecta queda capturada por el grado 2 (parsimonia).
+    assert r["best_degree"] == 2
+    assert r["r2_poly2"] > 0.99
+    assert r["coeffs"] is not None and len(r["coeffs"]) == r["best_degree"] + 1
+
+
+def test_monotona_no_lineal():
+    """Golden: monotona convexa de cola pesada -> 'monótona no-lineal'.
+
+    y = 1/(N+1-i)**2 es estrictamente creciente (Spearman ~ 1) pero su cola
+    explosiva hace que ni la recta ni un polinomio de grado 2/3 la ajusten
+    (R^2 polinomico < 0.5), de modo que el Pearson lineal NO capta la relacion
+    que el rango (Spearman) si ve. Construccion deterministica (sin azar).
+    """
+    n = 200
+    i = np.arange(n, dtype=float)
+    y = 1.0 / (n + 1 - i) ** 2
+
+    r = classify_relationship_type(list(i), list(y))
+    _assert_shape(r)
+
+    assert r["tipo"] == "monótona no-lineal"
+    assert r["best_degree"] is None
+    assert r["coeffs"] is None
+    # Spearman fuerte y claramente por encima del Pearson.
+    assert abs(r["spearman"]) >= 0.5
+    assert abs(r["spearman"]) - abs(r["pearson"]) >= 0.15
+
+
+def test_monotona_exponencial():
+    """DoD literal: y = exp(x) (monotona no-lineal) -> 'monótona no-lineal'.
+
+    exp es estrictamente creciente (Spearman = 1) pero el Pearson lineal queda
+    claramente por debajo (~0.86), así que la dominancia del rango la marca como
+    monótona no-lineal en vez de lineal o polinómica.
+    """
+    x = np.linspace(0.0, 5.0, 80)
+    y = np.exp(x)
+
+    r = classify_relationship_type(list(x), list(y))
+    _assert_shape(r)
+
+    assert r["tipo"] == "monótona no-lineal"
+    assert r["best_degree"] is None and r["coeffs"] is None
+    assert abs(r["spearman"]) >= 0.9
+    assert abs(r["spearman"]) - abs(r["pearson"]) >= 0.1
+
+
+def test_debil_sin_forma():
+    """Golden: x e y independientes (semilla fija) -> 'débil/sin forma'."""
+    rng = np.random.default_rng(0)
+    x = rng.normal(0.0, 1.0, 200)
+    y = rng.normal(0.0, 1.0, 200)
+
+    r = classify_relationship_type(list(x), list(y))
+    _assert_shape(r)
+
+    assert r["tipo"] == "débil/sin forma"
+    assert r["best_degree"] is None
+    assert r["coeffs"] is None
+    # Todas las senales son bajas.
+    assert abs(r["pearson"]) < 0.3
+    assert r["r2_linear"] < 0.1
+
+
+def test_lista_vacia_no_lanza():
+    """Edge: listas vacias -> dict debil canonico, sin lanzar."""
+    r = classify_relationship_type([], [])
+    _assert_shape(r)
+    assert r["tipo"] == "débil/sin forma"
+    assert r["pearson"] is None
+    assert r["r2_linear"] is None
+    assert r["spearman"] is None
+    assert r["r2_poly2"] is None
+    assert r["r2_poly3"] is None
+    assert r["best_degree"] is None
+    assert r["coeffs"] is None
+
+
+def test_longitudes_distintas_no_lanza():
+    """Edge: listas de distinta longitud -> empareja por indice, no lanza."""
+    # zip trunca a la longitud minima: solo 3 pares (< 5) -> debil.
+    r = classify_relationship_type([1, 2, 3, 4, 5, 6, 7, 8], [1.0, 2.0, 3.0])
+    _assert_shape(r)
+    assert r["tipo"] == "débil/sin forma"
+    assert r["best_degree"] is None
+
+
+def test_todos_none_no_lanza():
+    """Edge: todos los valores None -> ningun par valido -> debil, no lanza."""
+    r = classify_relationship_type([None, None, None, None, None, None],
+                                   [None, None, None, None, None, None])
+    _assert_shape(r)
+    assert r["tipo"] == "débil/sin forma"
+    assert r["coeffs"] is None
+
+
+def test_entradas_none_no_lanza():
+    """Edge: xs/ys None directamente -> debil, no lanza."""
+    assert classify_relationship_type(None, None)["tipo"] == "débil/sin forma"
+    assert classify_relationship_type([1.0, 2.0], None)["tipo"] == "débil/sin forma"
+
+
+def test_constante_no_lanza():
+    """Edge: ys constante (varianza ~0) -> debil, no lanza."""
+    r = classify_relationship_type([1, 2, 3, 4, 5, 6, 7], [5, 5, 5, 5, 5, 5, 5])
+    _assert_shape(r)
+    assert r["tipo"] == "débil/sin forma"
+
+
+def test_filtra_nan_inf_bool():
+    """Edge: pares con NaN/inf/bool/None se descartan por indice."""
+    nan = float("nan")
+    inf = float("inf")
+    # Solo i=0,1,2,3,4 quedan validos (5 pares) y forman una recta perfecta.
+    xs = [0.0, 1.0, 2.0, 3.0, 4.0, nan, inf, True, None]
+    ys = [1.0, 3.0, 5.0, 7.0, 9.0, 1.0, 2.0, 3.0, 4.0]
+    r = classify_relationship_type(xs, ys)
+    _assert_shape(r)
+    # Los 5 pares validos son y = 2x + 1 exacto -> lineal.
+    assert r["tipo"] == "lineal"
+    assert r["best_degree"] == 1

python/functions/datascience/extract_null_mask.md

@@ -0,0 +1,97 @@
+---
+name: extract_null_mask
+kind: function
+lang: py
+domain: datascience
+version: "1.0.0"
+purity: impure
+signature: "def extract_null_mask(query_fn, table: str, columns: list, max_rows: int = 5000) -> dict"
+description: "Extrae la mascara de nulos (1=falta / 0=presente) de una muestra de filas de una tabla, una lista 0/1 por columna alineada por fila, para alimentar el capitulo de calidad / patron de nulos de AutomaticEDA sin que el capitulo toque la base de datos. Recibe un lector read-only inyectado `query_fn(sql) -> dict` (mismo contrato que duckdb_query_readonly / pg_query / el `_q` de profile_table) y NO abre ninguna conexion por su cuenta. Construye UNA sola query que proyecta por cada columna `CASE WHEN \"col\" IS NULL THEN 1 ELSE 0 END` con identificadores escapados y LIMIT. Devuelve dict dict-no-throw: columns (efectivamente leidas, en orden), mask (lista int 0/1 por columna, misma longitud todas) y n. Una celda None se cuenta defensivamente como 1 (falta)."
+tags: [eda, nulls, missing, datascience, automatic-eda, extraction, read-only, duckdb, postgres, python]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: []
+params:
+  - name: query_fn
+    desc: "callable lector read-only del backend activo. Recibe un string SQL y devuelve un dict {'status':'ok','rows':[{col:val,...},...]} (mismo contrato que duckdb_query_readonly o el `_q` de profile_table). NO se abre ninguna conexion dentro de la funcion: toda la lectura pasa por query_fn. Si es None -> error."
+  - name: table
+    desc: "nombre de la tabla de la que muestrear la mascara de nulos. Se escapa con comillas dobles en la query. Vacio o None -> status error."
+  - name: columns
+    desc: "lista de nombres de columna a evaluar. Cada una produce una entrada en `mask` con una lista 0/1 paralela por fila (1=IS NULL, 0=presente). Cada nombre se escapa con comillas dobles. Vacia o None -> status error."
+  - name: max_rows
+    desc: "limite de filas a muestrear (clausula LIMIT). Default 5000. Protege frente a tablas enormes; con LIMIT obtienes el primer tramo, no un muestreo uniforme."
+output: "dict (nunca lanza). En exito: {'status':'ok','table':str,'columns':[str,...] (en orden),'mask':{col:[int 0/1,...],...} (1=falta/IS NULL, 0=presente; todas las listas con misma longitud = n),'n':int}. En error (sin lanzar): {'status':'error','error':str,'table':str,'columns':[],'mask':{},'n':0}. Errores: query_fn None, table vacia, columns vacia, o query_fn devuelve status!='ok' (se propaga su error)."
+tested: true
+tests: ["test_golden_mask_alineada", "test_celda_none_cuenta_como_falta", "test_columns_vacia_status_error", "test_query_fn_status_error_propaga", "test_query_fn_none_da_error_sin_reventar", "test_sql_contiene_case_y_limit"]
+test_file_path: "python/functions/datascience/extract_null_mask_test.py"
+file_path: "python/functions/datascience/extract_null_mask.py"
+---
+
+## Ejemplo
+
+```python
+import sys, os
+sys.path.insert(0, os.path.join("python", "functions"))
+from datascience.extract_null_mask import extract_null_mask
+from infra import duckdb_query_readonly
+
+# El lector read-only se inyecta como closure (igual que el `_q` de profile_table).
+db = "data/clientes.duckdb"
+def _q(sql):
+    return duckdb_query_readonly(db, sql)
+
+res = extract_null_mask(_q, "clientes", ["email", "telefono", "edad"])
+# res == {
+#   "status": "ok",
+#   "table": "clientes",
+#   "columns": ["email", "telefono", "edad"],
+#   "mask": {
+#     "email":    [0, 0, 1, 0, ...],   # fila 2 sin email
+#     "telefono": [1, 0, 1, 0, ...],
+#     "edad":     [0, 0, 0, 1, ...],
+#   },
+#   "n": 5000,
+# }
+
+# % de nulos por columna a partir de la muestra:
+pct = {c: 100 * sum(bits) / max(res["n"], 1) for c, bits in res["mask"].items()}
+
+# Se entrega al capitulo de calidad sin que este toque la BD:
+ctx = {"null_mask": res}
+```
+
+## Cuando usarla
+
+Cuando el capitulo de calidad / patron de nulos de AutomaticEDA necesita saber
+DONDE faltan los valores (no solo cuantos) y NO debe abrir la base de datos por
+su cuenta: extraes aqui la mascara 0/1 por columna alineada por fila y se la pasas
+en `ctx['null_mask']`. Usala siempre que quieras detectar co-ocurrencia de nulos
+(filas que fallan en varias columnas a la vez), calcular el % de nulos sobre una
+muestra, o pintar un heatmap de missingness reutilizando un unico lector read-only
+inyectado, en vez de hacer N `COUNT(*) WHERE col IS NULL` por separado.
+
+## Gotchas
+
+- **Impura**: lee de la base de datos a traves de `query_fn`. No abre conexiones
+  por su cuenta — depende por completo del lector inyectado. Sigue el estilo
+  dict-no-throw del grupo `eda`: nunca lanza; ante cualquier fallo devuelve
+  `{"status":"error","error":...}` con `columns=[]`, `mask={}`, `n=0`.
+- **`error_type` en el frontmatter es `error_go_core` por convencion del registry**
+  (toda funcion impura debe declararlo y el indexer lo exige), pero el codigo
+  NO lanza esa excepcion: degrada al dict de error. Es metadata, no comportamiento.
+- **Muestra, no censo**: con `LIMIT max_rows` obtienes el primer tramo de filas que
+  devuelva el backend, no un muestreo uniforme ni la tabla entera. El % de nulos
+  derivado es una estimacion sobre esa muestra; para el conteo exacto usa un
+  agregado `COUNT(*)`/`COUNT(col)` aparte.
+- **Alineacion por fila**: `mask[col][i]` corresponde a la misma fila `i` que
+  `mask[otra_col][i]`. Todas las listas tienen longitud `n`, asi que puedes cruzar
+  columnas por indice (co-ocurrencia de nulos) sin re-alinear.
+- **Defensa None -> 1**: el SQL ya devuelve 0/1, pero si una celda llega como `None`
+  (CASE no aplicado, columna ausente en la fila, backend que nulifica) se cuenta
+  como 1 (falta). Un valor inesperado no convertible a int se trata como presente (0).
+- **No loguear los datos crudos**: aunque `mask` es solo 0/1, los nombres de columna
+  pueden revelar el esquema. En trazas usa `n` y el numero de columnas, no el dict
+  completo.

python/functions/datascience/extract_null_mask.py

@@ -0,0 +1,101 @@
+"""extract_null_mask — extrae la mascara de nulos (1=falta / 0=presente) de una tabla.
+
+Lector read-only inyectado: recibe `query_fn(sql) -> dict` con el mismo contrato
+que duckdb_query_readonly / pg_query (y que el `_q` de profile_table):
+`{"status": "ok", "rows": [{col: val, ...}, ...]}`. Esta funcion NO abre ninguna
+conexion por su cuenta — solo usa `query_fn`. Construye UNA sola query que, por
+cada columna pedida, evalua `CASE WHEN "col" IS NULL THEN 1 ELSE 0 END` y devuelve
+una muestra de filas con esos bits. El resultado es un dict `mask` con una lista
+0/1 por columna, alineada por fila (1 = el valor falta / IS NULL, 0 = presente),
+listo para alimentar el capitulo de calidad / patron de nulos de AutomaticEDA sin
+que el capitulo toque la base de datos.
+
+Estilo dict-no-throw del grupo `eda`: nunca lanza; captura cualquier excepcion y
+degrada a `{"status": "error", "error": str, ...}`.
+"""
+
+
+def _to_bit(value):
+    """Coacciona el valor 0/1 del CASE a int de forma defensiva.
+
+    El SQL ya devuelve 0 (presente) o 1 (falta). Por si una celda llega como None
+    (el CASE no se aplico o el backend la nulifico), se cuenta como 1 (falta). El
+    resto se reduce a int: un entero distinto de 0 cuenta como 1 (falta), 0 como
+    presente. Un valor no convertible se trata como presente (0) — nunca lanza.
+    """
+    if value is None:
+        return 1
+    try:
+        return 1 if int(value) != 0 else 0
+    except (TypeError, ValueError):
+        return 0
+
+
+def extract_null_mask(query_fn, table, columns, max_rows=5000):
+    """Extrae la mascara de nulos (1=falta / 0=presente) de una muestra de la tabla.
+
+    Args:
+        query_fn: callable lector read-only del backend activo. Recibe un string
+            SQL y devuelve un dict {"status": "ok", "rows": [{col: val, ...}]}
+            (mismo contrato que duckdb_query_readonly / el `_q` de profile_table).
+            No se abre ninguna conexion aqui: toda la lectura pasa por query_fn.
+        table: nombre de la tabla. Se escapa con comillas dobles en la query.
+        columns: lista de nombres de columna a evaluar. Cada una produce una
+            entrada en `mask` con una lista 0/1 paralela por fila. Vacia o None ->
+            status error.
+        max_rows: limite de filas a muestrear (clausula LIMIT). Default 5000.
+
+    Returns:
+        dict (nunca lanza):
+            {
+              "status": "ok" | "error",
+              "error": str,                 # solo si status == "error"
+              "table": str,
+              "columns": [str, ...],        # columnas efectivamente leidas, en orden
+              "mask": {col: [int 0/1, ...], ...},  # alineada por fila, 1=falta, 0=presente
+              "n": int                      # nº de filas muestreadas
+            }
+        Todas las listas de `mask` tienen la misma longitud (= n).
+    """
+    base = {"status": "ok", "table": table, "columns": [], "mask": {}, "n": 0}
+    try:
+        if query_fn is None:
+            return {**base, "status": "error", "error": "query_fn es None"}
+        if not table:
+            return {**base, "status": "error", "error": "table es obligatorio"}
+        if not columns:
+            return {**base, "status": "error", "error": "columns vacío"}
+
+        # Identificadores escapados con comillas dobles (como hace profile_table)
+        # para tolerar nombres con mayusculas/espacios/palabras reservadas. Cada
+        # columna se proyecta como su propio bit IS NULL conservando el alias.
+        select_sql = ", ".join(
+            f'(CASE WHEN "{c}" IS NULL THEN 1 ELSE 0 END) AS "{c}"' for c in columns
+        )
+        sql = f'SELECT {select_sql} FROM "{table}" LIMIT {int(max_rows)}'
+
+        q = query_fn(sql)
+        if not isinstance(q, dict) or q.get("status") != "ok":
+            err = (
+                q.get("error", "query_fn fallo")
+                if isinstance(q, dict)
+                else "query_fn no devolvio un dict"
+            )
+            return {**base, "status": "error", "error": err}
+
+        rows = q.get("rows", []) or []
+        mask = {c: [] for c in columns}
+        for row in rows:
+            for c in columns:
+                # row.get tolera filas que no traigan la columna (None -> falta).
+                mask[c].append(_to_bit(row.get(c) if isinstance(row, dict) else None))
+
+        return {
+            "status": "ok",
+            "table": table,
+            "columns": list(columns),
+            "mask": mask,
+            "n": len(rows),
+        }
+    except Exception as e:  # noqa: BLE001 - dict-no-throw: degradar, nunca lanzar
+        return {**base, "status": "error", "error": str(e)}

python/functions/datascience/extract_null_mask_test.py

@@ -0,0 +1,116 @@
+"""Tests para extract_null_mask.
+
+No usa DuckDB real: inyecta un query_fn FAKE (closure) que devuelve filas
+predefinidas (simulando el SELECT de bits 0/1) y, opcionalmente, captura el SQL
+recibido para verificar la query generada (CASE WHEN ... IS NULL + LIMIT). Asi el
+test es autocontenido y no depende de ningun backend.
+"""
+
+import os
+import sys
+
+sys.path.insert(0, os.path.dirname(__file__))
+
+from extract_null_mask import extract_null_mask
+
+
+def _fake_query(rows, captured=None, status="ok", error=None):
+    """Crea un query_fn FAKE.
+
+    `captured` (lista opcional) recibe el SQL ejecutado para poder inspeccionarlo.
+    `status`/`error` permiten simular un fallo del backend.
+    """
+
+    def _q(sql):
+        if captured is not None:
+            captured.append(sql)
+        if status != "ok":
+            return {"status": "error", "error": error or "boom"}
+        return {"status": "ok", "rows": rows}
+
+    return _q
+
+
+def test_golden_mask_alineada():
+    """Golden: mask 0/1 por columna alineada por fila, n correcto, status ok."""
+    # Cada fila simula el SELECT (CASE WHEN col IS NULL THEN 1 ELSE 0 END) AS col.
+    rows = [
+        {"email": 0, "telefono": 1, "edad": 0},
+        {"email": 0, "telefono": 0, "edad": 1},
+        {"email": 1, "telefono": 1, "edad": 0},
+    ]
+    res = extract_null_mask(_fake_query(rows), "clientes", ["email", "telefono", "edad"])
+    assert res["status"] == "ok"
+    assert res["table"] == "clientes"
+    assert res["columns"] == ["email", "telefono", "edad"]
+    assert res["n"] == 3
+    assert res["mask"]["email"] == [0, 0, 1]
+    assert res["mask"]["telefono"] == [1, 0, 1]
+    assert res["mask"]["edad"] == [0, 1, 0]
+    # Todas las listas con la misma longitud.
+    assert all(len(v) == res["n"] for v in res["mask"].values())
+
+
+def test_celda_none_cuenta_como_falta():
+    """Una celda None se cuenta defensivamente como 1 (falta)."""
+    rows = [
+        {"email": 0, "telefono": None},
+        {"email": None, "telefono": 1},
+        {"email": 1, "telefono": 0},
+    ]
+    res = extract_null_mask(_fake_query(rows), "clientes", ["email", "telefono"])
+    assert res["status"] == "ok"
+    assert res["mask"]["email"] == [0, 1, 1]
+    assert res["mask"]["telefono"] == [1, 1, 0]
+    assert res["n"] == 3
+
+
+def test_columns_vacia_status_error():
+    """columns vacia -> status error con columns/mask/n vacios."""
+    res = extract_null_mask(_fake_query([]), "clientes", [])
+    assert res["status"] == "error"
+    assert "columns" in res["error"]
+    assert res["table"] == "clientes"
+    assert res["columns"] == []
+    assert res["mask"] == {}
+    assert res["n"] == 0
+
+
+def test_query_fn_status_error_propaga():
+    """query_fn que devuelve status != ok -> se propaga como error, mask {}."""
+    res = extract_null_mask(
+        _fake_query([], status="error", error="db locked"),
+        "clientes",
+        ["email"],
+    )
+    assert res["status"] == "error"
+    assert "db locked" in res["error"]
+    assert res["mask"] == {}
+    assert res["n"] == 0
+
+
+def test_query_fn_none_da_error_sin_reventar():
+    """query_fn None -> error degradado, sin excepcion."""
+    res = extract_null_mask(None, "clientes", ["email"])
+    assert res["status"] == "error"
+    assert res["columns"] == []
+    assert res["mask"] == {}
+    assert res["n"] == 0
+
+
+def test_sql_contiene_case_y_limit():
+    """La query genera un CASE WHEN IS NULL por columna escapada + LIMIT sobre la tabla."""
+    captured = []
+    rows = [{"email": 0}]
+    extract_null_mask(
+        _fake_query(rows, captured),
+        "clientes_tbl",
+        ["email"],
+        max_rows=123,
+    )
+    assert len(captured) == 1
+    sql = captured[0]
+    assert 'CASE WHEN "email" IS NULL THEN 1 ELSE 0 END' in sql
+    assert 'AS "email"' in sql
+    assert 'FROM "clientes_tbl"' in sql
+    assert "LIMIT 123" in sql

python/functions/datascience/missingness_corr_heatmap_figure.md

@@ -0,0 +1,103 @@
+---
+id: missingness_corr_heatmap_figure_py_datascience
+name: missingness_corr_heatmap_figure
+kind: function
+lang: py
+domain: datascience
+version: "1.0.0"
+purity: impure
+signature: "def missingness_corr_heatmap_figure(matrix, labels, title=\"Co-ocurrencia de ausencias\") -> \"matplotlib.figure.Figure\""
+description: "Construye una figura matplotlib (heatmap) de la matriz NxN de correlación de ausencias entre columnas: +1 = dos columnas suelen ser nulas a la vez, -1 = cuando una falta la otra está presente, 0 = ausencias independientes. Usa ax.imshow con coolwarm fijado a [-1,1], ticks con los labels truncados (X rotados 45º), colorbar y anota el valor de cada celda si N<=12. Devuelve un matplotlib.figure.Figure listo para rasterizar por el renderer del informe EDA (capítulo de datos faltantes). Backend Agg sin pyplot global; defensivo ante matrix/labels vacíos o celdas no numéricas (nunca lanza)."
+tags: [eda, missing, missingness, correlation, heatmap, matplotlib, figure, visualization, datascience, impure]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: [matplotlib]
+example: |
+  from datascience.missingness_corr_heatmap_figure import missingness_corr_heatmap_figure
+  matrix = [
+      [1.0, 0.82, -0.10],
+      [0.82, 1.0, 0.05],
+      [-0.10, 0.05, 1.0],
+  ]
+  labels = ["telefono", "movil", "email"]
+  fig = missingness_corr_heatmap_figure(matrix, labels, title="Co-ocurrencia de ausencias")
+tested: true
+tests:
+  - "test_returns_figure_with_axes"
+  - "test_empty_matrix_does_not_raise_and_returns_figure"
+  - "test_empty_labels_returns_message_figure"
+  - "test_large_matrix_omits_annotations"
+  - "test_ragged_and_non_numeric_cells_are_handled"
+test_file_path: "python/functions/datascience/missingness_corr_heatmap_figure_test.py"
+file_path: "python/functions/datascience/missingness_corr_heatmap_figure.py"
+params:
+  - name: matrix
+    desc: "Lista de listas (NxN) de floats en [-1,1]: la correlación de ausencias por pares de columnas. Puede venir vacía. Filas de longitud desigual se toleran (se rellenan/recortan a N); celdas None, NaN o no numéricas se coercen a 0.0. No se muta el original."
+  - name: labels
+    desc: "Lista de N nombres de columna, paralela a matrix. Puede venir vacía (devuelve figura \"sin columnas con ausencia variable\"). Se truncan a ~14 chars con elipsis para los ticks; los originales no se mutan."
+  - name: title
+    desc: "Título de la figura. Se trunca a ~60 chars con elipsis si es muy largo. Default \"Co-ocurrencia de ausencias\"."
+output: "Un matplotlib.figure.Figure (figsize 6.4x5.2, dpi 150) con un Axes heatmap (imshow vmin=-1, vmax=1, cmap coolwarm) más una colorbar etiquetada \"correlación de ausencias\". Ticks en ambos ejes con los labels truncados (X rotados 45º). Si N<=12 cada celda lleva su valor numérico anotado (texto blanco sobre celdas saturadas, oscuro sobre pálidas); con N grande se omiten las anotaciones para no saturar. Si matrix o labels vienen vacíos devuelve una Figure con texto centrado \"sin columnas con ausencia variable\"; cualquier error inesperado se captura y devuelve una Figure con el mensaje de error (nunca lanza). El caller rasteriza/cierra la figura; la función no la muestra ni la guarda."
+---
+
+## Ejemplo
+
+```python
+from datascience.missingness_corr_heatmap_figure import missingness_corr_heatmap_figure
+
+# Correlación de ausencias entre 3 columnas de contacto:
+# telefono y movil tienden a faltar juntos (0.82); email es casi independiente.
+matrix = [
+    [1.00, 0.82, -0.10],
+    [0.82, 1.00,  0.05],
+    [-0.10, 0.05, 1.00],
+]
+labels = ["telefono", "movil", "email"]
+
+fig = missingness_corr_heatmap_figure(
+    matrix,
+    labels,
+    title="Co-ocurrencia de ausencias",
+)
+
+# El renderer del informe lo rasteriza; aquí solo persistimos para inspección.
+fig.savefig("/tmp/missingness_heatmap.png")
+```
+
+## Cuando usarla
+
+Úsala en el capítulo de datos faltantes de un informe EDA cuando quieras ver de
+un vistazo qué columnas faltan juntas (mismo formulario sin rellenar, mismo
+proceso roto) frente a columnas cuyas ausencias son independientes. Pásale la
+matriz de correlación de ausencias (calculada sobre la máscara de nulos, p. ej.
+`df.isnull().corr()`) restringida a las columnas que de verdad tienen ausencia
+variable, junto con sus nombres. Es la pareja "estructura" del ranking de % de
+nulos: las barras dicen *cuánto* falta cada columna, este heatmap dice *si las
+ausencias están relacionadas* entre columnas.
+
+## Gotchas
+
+- **Impura por matplotlib.** Toca la maquinaria de render. Usa el backend `Agg`
+  y la API orientada a objetos `Figure`/`add_subplot` — NUNCA `pyplot.*` aquí,
+  para no tocar el estado global ni filtrar figuras entre llamadas. `pyplot` NO
+  es thread-safe; esta función evita ese riesgo construyendo el `Figure`
+  directamente, así que es segura de llamar en bucle desde el renderer.
+- **El caller cierra la figura.** Devuelve el `Figure` pero no lo muestra ni lo
+  guarda. Quien la consume debe rasterizarla y luego liberarla
+  (`matplotlib.pyplot.close(fig)`) para no acumular memoria en lotes grandes.
+- **Escala de color fija en [-1, 1].** `vmin=-1`, `vmax=1` están fijados a
+  propósito para que el color sea comparable entre informes y entre columnas. No
+  se autoescala al rango real de la matriz; valores fuera de `[-1, 1]` se
+  saturan al extremo del colormap.
+- **Anotaciones solo con N<=12.** Por encima de 12 columnas el grid de números
+  se vuelve ilegible y se omite; queda solo el color + la colorbar. Filtra a las
+  columnas con ausencia variable antes de llamar para no llegar a matrices
+  enormes.
+- **Defensiva, nunca lanza.** `matrix=[]`, `labels=[]`, filas cortas, celdas
+  `None`/`NaN`/no numéricas o cualquier error inesperado se manejan sin propagar:
+  en el peor caso devuelve una `Figure` con "sin columnas con ausencia variable"
+  o con el texto del error. No envuelvas la llamada en try/except por miedo a un
+  raise — no lo hay.

python/functions/datascience/missingness_corr_heatmap_figure.py

@@ -0,0 +1,158 @@
+"""Impure EDA helper: heatmap of missingness co-occurrence (`eda` group).
+
+Builds a matplotlib heatmap of the pairwise missingness correlation matrix of a
+dataset: a value near ``+1`` means two columns tend to be null together, near
+``-1`` means when one is null the other tends to be present, and ``0`` means
+their absences are independent. Returns a ready-to-rasterize
+``matplotlib.figure.Figure``; it never shows nor saves it.
+
+Impure because it touches matplotlib's rendering machinery. It uses the headless
+Agg backend and the object-oriented ``Figure`` API (no ``pyplot``) so it leaks no
+global state and is safe to call repeatedly from a report renderer.
+"""
+
+import matplotlib
+
+matplotlib.use("Agg")
+
+from matplotlib.figure import Figure  # noqa: E402
+
+# Muted gray for secondary text (no-data / fallback messages).
+_MUTED_TEXT = "#5f6b7a"
+# Soft red for the error fallback message (kept readable, not alarming).
+_ERROR_TEXT = "#b00020"
+
+
+def _truncate(text, width: int = 14) -> str:
+    """Truncate ``text`` to ``width`` chars, appending an ellipsis if cut."""
+    s = "" if text is None else str(text)
+    if len(s) <= width:
+        return s
+    if width <= 1:
+        return s[:width]
+    return s[: width - 1] + "…"
+
+
+def _message_figure(message: str, color: str = _MUTED_TEXT) -> "Figure":
+    """Return a fallback ``Figure`` carrying a single centered message."""
+    fig = Figure(figsize=(6.4, 4.0), dpi=150)
+    ax = fig.add_subplot(111)
+    ax.axis("off")
+    ax.text(
+        0.5,
+        0.5,
+        message,
+        ha="center",
+        va="center",
+        fontsize=12,
+        color=color,
+        wrap=True,
+        transform=ax.transAxes,
+    )
+    fig.tight_layout()
+    return fig
+
+
+def missingness_corr_heatmap_figure(
+    matrix,
+    labels,
+    title: str = "Co-ocurrencia de ausencias",
+) -> "matplotlib.figure.Figure":
+    """Build a heatmap figure of a missingness correlation matrix.
+
+    Renders an ``NxN`` matrix of missingness correlations in ``[-1, 1]`` with a
+    diverging ``coolwarm`` colormap (fixed ``vmin=-1``, ``vmax=1`` so the color
+    scale is comparable across reports). Both axes are tick-labelled with the
+    column names (truncated to ~14 chars; the X labels rotated 45°). A colorbar
+    is attached. When the matrix is small (``N <= 12``) each cell is annotated
+    with its numeric value; for larger matrices the annotations are omitted to
+    avoid an unreadable grid.
+
+    The function is fully defensive: empty/ragged/non-numeric input never raises.
+    When there is nothing valid to draw it returns a ``Figure`` carrying a
+    centered "sin columnas con ausencia variable" message, and any unexpected
+    error is caught and turned into a fallback ``Figure`` carrying the error text.
+
+    Args:
+        matrix: List of lists (``NxN``) of floats in ``[-1, 1]`` — the pairwise
+            missingness correlation. May be empty; rows of unequal length are
+            tolerated by treating the matrix as invalid only when it is empty or
+            its label count does not match. Non-numeric/``None`` cells are
+            coerced to ``0.0``.
+        labels: List of ``N`` column names, parallel to ``matrix``. May be empty.
+            Truncated for display; the originals are not mutated.
+        title: Figure title. Default "Co-ocurrencia de ausencias".
+
+    Returns:
+        A ``matplotlib.figure.Figure`` with a single heatmap Axes plus a
+        colorbar. The caller is responsible for rasterizing/closing it.
+    """
+    try:
+        # --- Validate shape: need a non-empty square-ish matrix with labels.
+        if (
+            not isinstance(matrix, (list, tuple))
+            or not isinstance(labels, (list, tuple))
+            or len(matrix) == 0
+            or len(labels) == 0
+        ):
+            return _message_figure("sin columnas con ausencia variable")
+
+        n = len(labels)
+        # Build a clean NxN grid: coerce each cell to float, default 0.0, pad/clip
+        # rows so a ragged input never crashes imshow.
+        grid = []
+        for i in range(n):
+            row_src = matrix[i] if i < len(matrix) else []
+            if not isinstance(row_src, (list, tuple)):
+                row_src = []
+            row = []
+            for j in range(n):
+                cell = row_src[j] if j < len(row_src) else 0.0
+                try:
+                    val = float(cell)
+                except (TypeError, ValueError):
+                    val = 0.0
+                if val != val:  # NaN guard.
+                    val = 0.0
+                row.append(val)
+            grid.append(row)
+
+        fig = Figure(figsize=(6.4, 5.2), dpi=150)
+        ax = fig.add_subplot(111)
+
+        im = ax.imshow(grid, vmin=-1, vmax=1, cmap="coolwarm", aspect="equal")
+
+        short = [_truncate(lab, 14) for lab in labels]
+        ax.set_xticks(range(n))
+        ax.set_yticks(range(n))
+        ax.set_xticklabels(short, rotation=45, ha="right", fontsize=8)
+        ax.set_yticklabels(short, fontsize=8)
+
+        # Annotate each cell only when the grid is small enough to stay legible.
+        if n <= 12:
+            for i in range(n):
+                for j in range(n):
+                    val = grid[i][j]
+                    # White text over saturated (dark) cells, dark over pale.
+                    txt_color = "white" if abs(val) >= 0.55 else "#202020"
+                    ax.text(
+                        j,
+                        i,
+                        f"{val:.2f}",
+                        ha="center",
+                        va="center",
+                        fontsize=7,
+                        color=txt_color,
+                    )
+
+        cbar = fig.colorbar(im, ax=ax, fraction=0.046, pad=0.04)
+        cbar.ax.tick_params(labelsize=8)
+        cbar.set_label("correlación de ausencias", fontsize=8)
+
+        if title:
+            ax.set_title(_truncate(title, 60), fontsize=12, loc="center", pad=10)
+
+        fig.tight_layout()
+        return fig
+    except Exception as exc:  # noqa: BLE001 — never raise from a figure builder.
+        return _message_figure(f"error al dibujar heatmap: {exc}", color=_ERROR_TEXT)

python/functions/datascience/missingness_corr_heatmap_figure_test.py

@@ -0,0 +1,62 @@
+"""Tests para missingness_corr_heatmap_figure (heatmap de ausencias, grupo eda).
+
+Usa el backend Agg sin pyplot; no muestra ni guarda figuras. Cada test cierra
+explícitamente la Figure construida (matplotlib.pyplot.close) para no acumular
+estado entre tests.
+"""
+
+import matplotlib
+
+matplotlib.use("Agg")
+
+import matplotlib.pyplot as plt  # noqa: E402
+from matplotlib.figure import Figure  # noqa: E402
+
+from missingness_corr_heatmap_figure import missingness_corr_heatmap_figure
+
+
+def _identity_matrix(n):
+    """Matriz NxN con diagonal 1.0 y resto 0.0 (correlación de ausencias)."""
+    return [[1.0 if i == j else 0.0 for j in range(n)] for i in range(n)]
+
+
+def test_returns_figure_with_axes():
+    matrix = [[1.0, 0.3, -0.2], [0.3, 1.0, 0.5], [-0.2, 0.5, 1.0]]
+    labels = ["edad", "ingresos", "ciudad"]
+    fig = missingness_corr_heatmap_figure(matrix, labels, title="ausencias")
+    assert isinstance(fig, Figure)
+    # Heatmap (>=1 axes) + colorbar añade su propio Axes -> al menos 1.
+    assert len(fig.axes) >= 1
+    plt.close(fig)
+
+
+def test_empty_matrix_does_not_raise_and_returns_figure():
+    fig = missingness_corr_heatmap_figure([], [], title="vacía")
+    assert isinstance(fig, Figure)
+    assert len(fig.axes) >= 1
+    plt.close(fig)
+
+
+def test_empty_labels_returns_message_figure():
+    fig = missingness_corr_heatmap_figure([[1.0]], [], title="sin labels")
+    assert isinstance(fig, Figure)
+    plt.close(fig)
+
+
+def test_large_matrix_omits_annotations():
+    n = 16
+    fig = missingness_corr_heatmap_figure(
+        _identity_matrix(n), [f"col_{i}" for i in range(n)]
+    )
+    assert isinstance(fig, Figure)
+    assert len(fig.axes) >= 1
+    plt.close(fig)
+
+
+def test_ragged_and_non_numeric_cells_are_handled():
+    # Fila corta + celda None + celda string -> se rellenan/coercen sin lanzar.
+    matrix = [[1.0, None], ["x", 1.0, 0.5]]
+    labels = ["a", "b"]
+    fig = missingness_corr_heatmap_figure(matrix, labels)
+    assert isinstance(fig, Figure)
+    plt.close(fig)

python/functions/datascience/missingness_correlation.md

@@ -0,0 +1,68 @@
+---
+name: missingness_correlation
+kind: function
+lang: py
+domain: datascience
+version: "1.0.0"
+purity: pure
+signature: "def missingness_correlation(null_mask: dict, top_k: int = 20) -> dict"
+description: "Co-ocurrencia de ausencias: nucleo del capitulo de missingness del grupo eda. Recibe la mascara binaria de nulos de una tabla (1 = falta, 0 = presente, alineada por fila) y mide hasta que punto las columnas faltan juntas. Calcula la matriz de correlacion de Pearson entre los vectores binarios de ausencia de las columnas con varianza (al menos un 1 y un 0), mas las cifras de solapamiento de conjuntos por par (co-missing, either-missing, Jaccard). Excluye las columnas constantes en su ausencia (correlacion indefinida) y reporta cuantas. Compone la funcion atomica pearson del registry; no la reimplementa. Lectura defensiva; NUNCA lanza."
+tags: [eda, missingness, correlation, pearson, co-occurrence, jaccard, datascience]
+params:
+  - name: null_mask
+    desc: "dict {col: [int 0/1, ...]} con la mascara de ausencias de la tabla, alineada por fila: 1 = el valor falta en esa fila, 0 = presente. Todas las listas se asumen de la misma longitud (numero de filas). Valores truthy distintos de 0 se tratan como ausencia; entradas no-lista se ignoran sin romper."
+  - name: top_k
+    desc: "Numero maximo de pares a devolver en `pairs`, ordenados por valor absoluto de correlacion descendente. Default 20. Solo limita la lista de pares; la matriz cubre siempre todas las columnas con varianza."
+output: "dict con: columns (columnas con varianza en la ausencia, en orden de entrada); matrix (len(columns) x len(columns) de correlacion de Pearson entre las mascaras binarias, diagonal 1.0); pairs (hasta top_k pares i<j ordenados por |corr| desc, cada uno {a, b, corr, co_missing, either_missing, jaccard} donde co_missing = filas en que ambas faltan, either_missing = filas en que al menos una falta, jaccard = co_missing/either_missing o 0.0 si either_missing=0); n_excluded (nº de columnas con algun nulo pero sin varianza, constantes en la ausencia); excluded_cols (esas columnas en orden de entrada). Si hay <2 columnas con varianza, columns/matrix/pairs van vacios pero n_excluded/excluded_cols se rellenan. NUNCA lanza."
+uses_functions: [pearson_py_datascience]
+uses_types: []
+returns: []
+returns_optional: false
+error_type: ""
+imports: []
+tested: true
+tests: ["test_co_ocurrencia_fuerte_corr_uno_jaccard_uno", "test_ausencias_disjuntas_corr_negativa_jaccard_cero", "test_columna_sin_varianza_se_excluye", "test_menos_de_dos_columnas_con_varianza_vacio_pero_cuenta_excluidas", "test_mask_vacio_todo_vacio", "test_top_k_limita_pares", "test_no_lanza_con_entradas_raras"]
+test_file_path: "python/functions/datascience/missingness_correlation_test.py"
+file_path: "python/functions/datascience/missingness_correlation.py"
+---
+
+## Ejemplo
+
+```python
+import sys, os
+sys.path.insert(0, os.path.join("python", "functions"))
+from datascience.missingness_correlation import missingness_correlation
+
+# Mascara de ausencias de 6 filas. 1 = falta, 0 = presente.
+mask = {
+    "ingresos":  [1, 0, 1, 0, 1, 0],   # falta junto a "deducciones"
+    "deducciones": [1, 0, 1, 0, 1, 0], # mismas filas que "ingresos"
+    "telefono":  [0, 0, 0, 1, 0, 0],   # casi siempre presente
+    "verificado": [1, 1, 1, 1, 1, 1],  # siempre ausente -> constante, excluida
+}
+out = missingness_correlation(mask, top_k=10)
+
+print(out["columns"])        # ['ingresos', 'deducciones', 'telefono']
+print(out["n_excluded"])     # 1
+print(out["excluded_cols"])  # ['verificado']
+
+# El par mas fuerte: ingresos y deducciones faltan siempre juntas.
+top = out["pairs"][0]
+print(top["a"], top["b"], round(top["corr"], 3))  # ingresos deducciones 1.0
+print(top["co_missing"], top["either_missing"], top["jaccard"])  # 3 3 1.0
+```
+
+## Cuando usarla
+
+- Usala en el capitulo de **missingness** de `AutomaticEDA` cuando ya tengas la mascara binaria de nulos por columna y quieras detectar **patrones de ausencia conjunta**: que columnas faltan siempre juntas (posible misma fuente/proceso roto) y cuales faltan de forma independiente.
+- Cuando necesites ordenar los pares de columnas por fuerza de co-ocurrencia (|corr|) para priorizar que bloques de ausencia investigar o imputar juntos.
+- Cuando quieras la cifra de solapamiento de conjuntos (Jaccard, co-missing) ademas de la correlacion lineal, para distinguir "faltan juntas" de "estan presentes juntas".
+- Antes de elegir una estrategia de imputacion: dos columnas con corr de ausencia ~1.0 no aportan informacion independiente sobre por que falta la otra.
+
+## Gotchas
+
+- Funcion pura, sin I/O y determinista. Lectura defensiva: entradas no-dict, columnas no-lista o vacias se ignoran sin lanzar.
+- Solo entran al calculo las columnas con **varianza en la ausencia** (al menos un 1 y al menos un 0). Una columna siempre-presente (todo 0) no aporta ausencia y **no** se cuenta como excluida; una columna siempre-ausente o constante con nulos (todo 1) tiene correlacion indefinida y se excluye, sumando a `n_excluded` / `excluded_cols`.
+- Con menos de 2 columnas con varianza, `columns`/`matrix`/`pairs` quedan vacios pero `n_excluded`/`excluded_cols` se rellenan igual — el caller debe contemplar el caso "sin pares".
+- La correlacion es la de Pearson sobre vectores binarios (equivale al coeficiente phi). El signo importa: corr negativa = las ausencias tienden a ser **complementarias** (cuando una falta, la otra suele estar presente).
+- Asume todas las listas alineadas por fila y de la misma longitud. Si vienen de longitudes distintas, `pearson` opera sobre el solapamiento que permita `zip` y degrada a 0.0 cuando no hay varianza efectiva; alinea la mascara antes de llamar.

python/functions/datascience/missingness_correlation.py

@@ -0,0 +1,120 @@
+"""Co-ocurrencia de ausencias: matriz de correlacion de Pearson entre mascaras de nulos.
+
+Funcion pura del grupo eda, nucleo del capitulo de missingness. Recibe la mascara
+binaria de ausencias de una tabla (1 = falta, 0 = presente, alineada por fila) y
+mide hasta que punto las columnas faltan juntas. Para cada par de columnas con
+varianza en su ausencia calcula la correlacion de Pearson entre los vectores
+binarios, mas las cifras de solapamiento de conjuntos (co-missing, either-missing,
+Jaccard). Compone la funcion atomica `pearson` del registry; no reimplementa la
+correlacion. Lectura defensiva; NUNCA lanza.
+"""
+
+from datascience import pearson
+
+
+def missingness_correlation(null_mask, top_k=20) -> dict:
+    """Correlacion de co-ocurrencia de ausencias entre columnas.
+
+    Args:
+        null_mask: dict {col: [int 0/1, ...]} alineado por fila (1 = el valor
+            falta en esa fila). Todas las listas se asumen de la misma longitud.
+        top_k: numero maximo de pares a devolver, ordenados por |corr| desc.
+
+    Returns:
+        dict con:
+          - columns: columnas con varianza en la ausencia (al menos un 1 y al
+            menos un 0), en orden de entrada.
+          - matrix: matriz len(columns) x len(columns) de correlacion de Pearson
+            entre las mascaras binarias, diagonal 1.0.
+          - pairs: lista de hasta top_k pares (i<j) ordenados por |corr| desc.
+            Cada par: {a, b, corr, co_missing, either_missing, jaccard}.
+          - n_excluded: numero de columnas con algun nulo pero sin varianza
+            (constantes en la ausencia: siempre presentes o siempre ausentes).
+          - excluded_cols: lista de esas columnas (en orden de entrada).
+
+        Si hay menos de 2 columnas con varianza, columns/matrix/pairs van vacios
+        pero n_excluded/excluded_cols se rellenan igualmente. NUNCA lanza.
+    """
+    # Salida base, defensiva ante entradas no-dict.
+    result = {
+        "columns": [],
+        "matrix": [],
+        "pairs": [],
+        "n_excluded": 0,
+        "excluded_cols": [],
+    }
+
+    if not isinstance(null_mask, dict) or not null_mask:
+        return result
+
+    varying = []          # columnas con varianza en la ausencia
+    varying_vecs = []     # sus vectores binarios saneados (floats 0.0/1.0)
+    excluded_cols = []    # columnas con nulos pero sin varianza (constantes)
+
+    for col, raw in null_mask.items():
+        if not isinstance(raw, (list, tuple)):
+            continue
+        # Sanea a 0/1: cualquier valor truthy distinto de 0 cuenta como ausencia.
+        vec = [1 if bool(v) else 0 for v in raw]
+        if not vec:
+            continue
+        ones = sum(vec)
+        zeros = len(vec) - ones
+        if ones > 0 and zeros > 0:
+            varying.append(col)
+            varying_vecs.append([float(v) for v in vec])
+        elif ones > 0:
+            # Tiene nulos pero todos (constante en la ausencia): sin varianza.
+            excluded_cols.append(col)
+        # ones == 0 -> columna siempre presente, sin nulos: no se cuenta como
+        # excluida (no aporta ausencia al analisis de co-ocurrencia).
+
+    result["n_excluded"] = len(excluded_cols)
+    result["excluded_cols"] = excluded_cols
+
+    n = len(varying)
+    if n < 2:
+        return result
+
+    result["columns"] = list(varying)
+
+    # Matriz de correlacion de Pearson, diagonal 1.0.
+    matrix = [[0.0] * n for _ in range(n)]
+    for i in range(n):
+        matrix[i][i] = 1.0
+    for i in range(n):
+        for j in range(i + 1, n):
+            r = pearson(varying_vecs[i], varying_vecs[j])
+            matrix[i][j] = r
+            matrix[j][i] = r
+    result["matrix"] = matrix
+
+    # Pares con cifras de solapamiento de conjuntos.
+    pairs = []
+    for i in range(n):
+        vi = varying_vecs[i]
+        for j in range(i + 1, n):
+            vj = varying_vecs[j]
+            co_missing = 0
+            either_missing = 0
+            for a, b in zip(vi, vj):
+                a_miss = a != 0.0
+                b_miss = b != 0.0
+                if a_miss and b_miss:
+                    co_missing += 1
+                if a_miss or b_miss:
+                    either_missing += 1
+            jaccard = co_missing / either_missing if either_missing > 0 else 0.0
+            pairs.append({
+                "a": varying[i],
+                "b": varying[j],
+                "corr": matrix[i][j],
+                "co_missing": co_missing,
+                "either_missing": either_missing,
+                "jaccard": jaccard,
+            })
+
+    pairs.sort(key=lambda p: abs(p["corr"]), reverse=True)
+    result["pairs"] = pairs[:top_k] if top_k is not None and top_k >= 0 else pairs
+
+    return result

python/functions/datascience/missingness_correlation_test.py

@@ -0,0 +1,115 @@
+"""Tests para missingness_correlation."""
+
+from datascience.missingness_correlation import missingness_correlation
+
+
+def test_co_ocurrencia_fuerte_corr_uno_jaccard_uno():
+    # a y b faltan EXACTAMENTE en las mismas filas -> corr 1.0, jaccard 1.0.
+    mask = {
+        "a": [1, 0, 1, 0, 1, 0],
+        "b": [1, 0, 1, 0, 1, 0],
+    }
+    out = missingness_correlation(mask)
+    assert out["columns"] == ["a", "b"]
+    assert out["n_excluded"] == 0
+    # Diagonal 1.0, off-diagonal ~1.0.
+    assert out["matrix"][0][0] == 1.0
+    assert out["matrix"][1][1] == 1.0
+    assert abs(out["matrix"][0][1] - 1.0) < 1e-9
+    assert len(out["pairs"]) == 1
+    pair = out["pairs"][0]
+    assert {pair["a"], pair["b"]} == {"a", "b"}
+    assert abs(pair["corr"] - 1.0) < 1e-9
+    assert pair["co_missing"] == 3       # filas 0,2,4
+    assert pair["either_missing"] == 3   # mismas filas
+    assert abs(pair["jaccard"] - 1.0) < 1e-9
+
+
+def test_ausencias_disjuntas_corr_negativa_jaccard_cero():
+    # a y b nunca faltan en la misma fila -> co_missing 0, jaccard 0, corr <= 0.
+    mask = {
+        "a": [1, 1, 0, 0],
+        "b": [0, 0, 1, 1],
+    }
+    out = missingness_correlation(mask)
+    assert out["columns"] == ["a", "b"]
+    pair = out["pairs"][0]
+    assert pair["co_missing"] == 0
+    assert pair["either_missing"] == 4
+    assert pair["jaccard"] == 0.0
+    # Solapamiento nulo + ausencias complementarias -> correlacion negativa.
+    assert pair["corr"] < 0.0
+    assert abs(pair["corr"] - out["matrix"][0][1]) < 1e-12
+
+
+def test_columna_sin_varianza_se_excluye():
+    # c esta siempre presente (todo 0): no aporta ausencia -> no entra ni como
+    # excluida. d esta siempre ausente (todo 1): tiene nulos pero sin varianza
+    # -> excluida y n_excluded incrementa. a y b tienen varianza.
+    mask = {
+        "a": [1, 0, 1, 0],
+        "b": [1, 0, 0, 0],
+        "c": [0, 0, 0, 0],   # siempre presente
+        "d": [1, 1, 1, 1],   # siempre ausente, constante
+    }
+    out = missingness_correlation(mask)
+    assert out["columns"] == ["a", "b"]
+    assert "d" in out["excluded_cols"]
+    assert "c" not in out["excluded_cols"]
+    assert out["n_excluded"] == 1
+    # Matriz solo de las columnas con varianza.
+    assert len(out["matrix"]) == 2
+    assert len(out["matrix"][0]) == 2
+
+
+def test_menos_de_dos_columnas_con_varianza_vacio_pero_cuenta_excluidas():
+    # Solo una columna con varianza (a) + una constante-ausente (d).
+    mask = {
+        "a": [1, 0, 1, 0],
+        "d": [1, 1, 1, 1],
+    }
+    out = missingness_correlation(mask)
+    assert out["columns"] == []
+    assert out["matrix"] == []
+    assert out["pairs"] == []
+    assert out["n_excluded"] == 1
+    assert out["excluded_cols"] == ["d"]
+
+
+def test_mask_vacio_todo_vacio():
+    out = missingness_correlation({})
+    assert out == {
+        "columns": [],
+        "matrix": [],
+        "pairs": [],
+        "n_excluded": 0,
+        "excluded_cols": [],
+    }
+
+
+def test_top_k_limita_pares():
+    # 4 columnas con varianza -> 6 pares; top_k=2 deja 2.
+    mask = {
+        "a": [1, 0, 1, 0, 0],
+        "b": [1, 0, 0, 1, 0],
+        "c": [0, 1, 1, 0, 1],
+        "d": [1, 1, 0, 0, 1],
+    }
+    out = missingness_correlation(mask, top_k=2)
+    assert len(out["columns"]) == 4
+    assert len(out["pairs"]) == 2
+    # Ordenados por |corr| desc.
+    assert abs(out["pairs"][0]["corr"]) >= abs(out["pairs"][1]["corr"])
+
+
+def test_no_lanza_con_entradas_raras():
+    # Valores no-lista y no-dict no deben romper.
+    assert missingness_correlation(None)["columns"] == []
+    mask = {
+        "a": [1, 0, 1, 0],
+        "b": [1, 0, 1, 0],
+        "bad": "not a list",
+        "empty": [],
+    }
+    out = missingness_correlation(mask)
+    assert out["columns"] == ["a", "b"]

python/functions/datascience/missingness_overview.md

@@ -0,0 +1,99 @@
+---
+id: missingness_overview_py_datascience
+name: missingness_overview
+kind: function
+lang: py
+domain: datascience
+version: "1.0.0"
+purity: pure
+signature: "def missingness_overview(null_mask) -> dict"
+description: "Resumen de ausencias a nivel de dataset a partir de una máscara de nulos 0/1 por columna ({col: [1=falta, 0=presente]} alineada por fila). Calcula celdas y porcentaje de datos faltantes, cuántas columnas tienen algún nulo y cuántas filas son completas vs. incompletas. Estilo dict-no-throw del grupo eda: nunca lanza. Lectura defensiva — no-dict o dict vacío devuelve todo a 0; columnas no-lista se tratan como vacías; listas de longitud distinta se alinean a la longitud máxima rellenando la cola corta como presente (0); valores None/no-int cuentan como presente; sin ZeroDivisionError."
+tags: [eda, missing, missingness, nulls, profiling, datascience, pure]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: ""
+imports: []
+example: |
+  from datascience.missingness_overview import missingness_overview
+  mask = {
+      "a": [1, 0, 0, 0, 1],
+      "b": [1, 0, 1, 0, 0],
+      "c": [0, 0, 0, 0, 1],
+  }
+  missingness_overview(mask)
+  # n_missing_cells=5, missing_cell_pct≈33.33, complete_rows=2, incomplete_rows=3
+tested: true
+tests:
+  - "test_cooccurrence_three_cols_exact"
+  - "test_empty_dict_all_zero"
+  - "test_output_keys_contract"
+  - "test_not_a_dict_returns_zero"
+  - "test_no_nulls_all_complete"
+  - "test_none_values_treated_as_present"
+  - "test_unequal_lengths_pad_with_max"
+  - "test_columns_present_but_no_rows"
+  - "test_never_raises_on_garbage"
+test_file_path: "python/functions/datascience/missingness_overview_test.py"
+file_path: "python/functions/datascience/missingness_overview.py"
+params:
+  - name: null_mask
+    desc: "Dict {col_name: [int 0/1, ...]} con la máscara de nulos por columna, alineada por fila (1 = el valor falta, 0 = el valor está presente). Normalmente todas las listas tienen la misma longitud = nº de filas. Lectura defensiva: si no es dict o está vacío se devuelve todo a 0; columnas cuyo valor no es lista/tupla se tratan como vacías; listas de longitud distinta se alinean a la longitud máxima (las posiciones inexistentes de las columnas más cortas cuentan como presentes, 0); valores None o no enteros cuentan como presentes."
+output: "Dict con exactamente 9 claves, todas siempre presentes (la función nunca lanza): n_rows (longitud de fila = longitud máxima entre columnas, 0 si vacío), n_cols (nº de columnas), n_cols_with_null (columnas con >=1 falta), n_missing_cells (suma total de 1s), missing_cell_pct (0-100 = n_missing_cells / (n_rows*n_cols) * 100), complete_rows (filas sin ninguna falta), incomplete_rows (filas con >=1 falta), complete_pct (0-100), incomplete_pct (0-100). Los porcentajes son 0.0 cuando el denominador es 0 (sin ZeroDivisionError)."
+---
+
+## Ejemplo
+
+```python
+from datascience.missingness_overview import missingness_overview
+
+# Máscara de nulos por columna: 1 = falta, 0 = presente, alineada por fila.
+mask = {
+    "a": [1, 0, 0, 0, 1],
+    "b": [1, 0, 1, 0, 0],
+    "c": [0, 0, 0, 0, 1],
+}
+
+missingness_overview(mask)
+# {
+#   "n_rows": 5,
+#   "n_cols": 3,
+#   "n_cols_with_null": 3,      # a, b y c tienen al menos una falta
+#   "n_missing_cells": 5,       # 2 (a) + 2 (b) + 1 (c)
+#   "missing_cell_pct": 33.33,  # 5 / (5*3) * 100
+#   "complete_rows": 2,         # filas 1 y 3 sin ninguna falta
+#   "incomplete_rows": 3,       # filas 0 (a&b), 2 (b), 4 (a&c)
+#   "complete_pct": 40.0,       # 2 / 5 * 100
+#   "incomplete_pct": 60.0,     # 3 / 5 * 100
+# }
+
+missingness_overview({})
+# Todo a 0: {"n_rows": 0, "n_cols": 0, "n_cols_with_null": 0,
+#            "n_missing_cells": 0, "missing_cell_pct": 0.0,
+#            "complete_rows": 0, "incomplete_rows": 0,
+#            "complete_pct": 0.0, "incomplete_pct": 0.0}
+```
+
+## Cuando usarla
+
+Úsala al perfilar un dataset cuando ya tienes una máscara de nulos 0/1 por
+columna (p. ej. derivada del paso de carga/perfilado del EDA) y quieres la foto
+global de ausencias en una llamada: cuánta proporción de celdas falta, cuántas
+columnas están afectadas y, sobre todo, cuántas filas quedan completas vs.
+incompletas. Es el bloque resumen del capítulo de calidad/missingness de un EDA,
+y la base para decidir estrategias de imputación o de borrado de filas. Como es
+pura y dict-no-throw, puedes alimentarla con la máscara tal cual sin validarla
+antes: entradas malformadas degradan a ceros en vez de romper el pipeline.
+
+## Gotchas
+
+- **`n_rows` es la longitud máxima entre columnas.** Con listas de longitud
+  desigual, las posiciones que faltan en las columnas más cortas se cuentan como
+  presentes (`0`); no se descartan filas. En el caso normal (todas las listas de
+  igual longitud) `n_rows` es simplemente esa longitud.
+- **Solo el valor exacto `1` cuenta como falta.** `None`, `0`, cadenas y
+  cualquier otro valor se tratan como presentes. `True` (== 1) también cuenta
+  como falta por la igualdad.
+- **Porcentajes en escala 0-100**, no fracciones. División por cero protegida:
+  con `n_rows*n_cols == 0` los porcentajes salen `0.0`.

python/functions/datascience/missingness_overview.py

@@ -0,0 +1,116 @@
+"""Pure EDA helper: dataset-level missingness overview from a 0/1 null mask.
+
+Part of the `eda` capability group. Consumes a per-column null mask
+(``{col_name: [int 0/1, ...]}`` aligned by row, ``1`` = value is missing,
+``0`` = value is present) and derives dataset-wide missingness metrics: cell
+count and percentage of missing data, how many columns carry any null, and how
+many rows are complete vs. incomplete.
+
+Dict-no-throw style of the `eda` group: it NEVER raises. A non-dict, an empty
+dict, malformed columns, ragged lists or non-int cell values all degrade
+gracefully to the zero/contract output. Stdlib only.
+
+Ragged-length policy: columns are allowed to have different lengths. ``n_rows``
+is the **maximum** column length; positions that don't exist in a shorter
+column are treated as present (``0``). This keeps the ``n_rows * n_cols`` cell
+grid well defined without dropping rows.
+"""
+
+
+def _is_missing(value) -> int:
+    """Return ``1`` iff ``value`` denotes a missing cell, else ``0``.
+
+    Only an exact equality to ``1`` (covers ``int`` ``1`` and ``float`` ``1.0``)
+    counts as missing. ``None``, ``0``, strings and any other value are treated
+    as present. The comparison cannot raise for standard inputs.
+    """
+    try:
+        return 1 if value == 1 else 0
+    except Exception:
+        return 0
+
+
+def missingness_overview(null_mask) -> dict:
+    """Summarize dataset-level missingness from a 0/1 null mask.
+
+    Args:
+        null_mask: Dict ``{col_name: [int 0/1, ...]}`` where each list is aligned
+            by row (``1`` = missing, ``0`` = present). Lists are normally all the
+            same length (= number of rows). Defensive: a non-dict or empty dict
+            returns the all-zero contract; non-list columns are treated as empty;
+            ragged lists are aligned to the maximum length, padding the missing
+            tail of shorter columns as present (``0``); ``None`` / non-int cells
+            count as present.
+
+    Returns:
+        Dict with exactly these keys, all always present (the function never
+        raises): ``n_rows``, ``n_cols``, ``n_cols_with_null``,
+        ``n_missing_cells``, ``missing_cell_pct`` (0-100), ``complete_rows``,
+        ``incomplete_rows``, ``complete_pct`` (0-100), ``incomplete_pct``
+        (0-100). Percentages are ``0.0`` when the denominator is zero (no
+        ``ZeroDivisionError``).
+    """
+    zero = {
+        "n_rows": 0,
+        "n_cols": 0,
+        "n_cols_with_null": 0,
+        "n_missing_cells": 0,
+        "missing_cell_pct": 0.0,
+        "complete_rows": 0,
+        "incomplete_rows": 0,
+        "complete_pct": 0.0,
+        "incomplete_pct": 0.0,
+    }
+
+    if not isinstance(null_mask, dict) or not null_mask:
+        return dict(zero)
+
+    # Normalize every column to a list; non-list columns become empty.
+    cols = {}
+    for name, seq in null_mask.items():
+        cols[name] = seq if isinstance(seq, (list, tuple)) else []
+
+    n_cols = len(cols)
+    lengths = [len(seq) for seq in cols.values()]
+    n_rows = max(lengths) if lengths else 0
+
+    if n_rows == 0:
+        # Columns exist but carry no rows: everything zero except n_cols.
+        out = dict(zero)
+        out["n_cols"] = n_cols
+        return out
+
+    n_missing_cells = 0
+    n_cols_with_null = 0
+    row_has_missing = [False] * n_rows
+
+    for seq in cols.values():
+        col_len = len(seq)
+        col_has_null = False
+        for r in range(n_rows):
+            if r < col_len and _is_missing(seq[r]):
+                n_missing_cells += 1
+                row_has_missing[r] = True
+                col_has_null = True
+        if col_has_null:
+            n_cols_with_null += 1
+
+    incomplete_rows = sum(1 for flag in row_has_missing if flag)
+    complete_rows = n_rows - incomplete_rows
+
+    total_cells = n_rows * n_cols
+    missing_cell_pct = (n_missing_cells / total_cells * 100.0) if total_cells else 0.0
+    complete_pct = complete_rows / n_rows * 100.0
+    incomplete_pct = incomplete_rows / n_rows * 100.0
+
+    return {
+        "n_rows": n_rows,
+        "n_cols": n_cols,
+        "n_cols_with_null": n_cols_with_null,
+        "n_missing_cells": n_missing_cells,
+        "missing_cell_pct": missing_cell_pct,
+        "complete_rows": complete_rows,
+        "incomplete_rows": incomplete_rows,
+        "complete_pct": complete_pct,
+        "incomplete_pct": incomplete_pct,
+    }

python/functions/datascience/missingness_overview_test.py

@@ -0,0 +1,146 @@
+"""Tests para missingness_overview."""
+
+import sys
+import os
+
+import pytest
+
+sys.path.insert(0, os.path.dirname(__file__))
+
+from missingness_overview import missingness_overview
+
+
+# Output contract: every call returns exactly these 9 keys.
+EXPECTED_KEYS = {
+    "n_rows",
+    "n_cols",
+    "n_cols_with_null",
+    "n_missing_cells",
+    "missing_cell_pct",
+    "complete_rows",
+    "incomplete_rows",
+    "complete_pct",
+    "incomplete_pct",
+}
+
+
+def test_cooccurrence_three_cols_exact():
+    # 3 columns, 5 rows. Hand-computed expectations:
+    #   col a missing at rows 0, 4      -> 2
+    #   col b missing at rows 0, 2      -> 2
+    #   col c missing at row  4         -> 1
+    #   n_missing_cells = 5, total_cells = 5*3 = 15 -> 33.333...%
+    #   row 0 (a&b co-occur)  -> incomplete
+    #   row 1 (all present)   -> complete
+    #   row 2 (b only)        -> incomplete
+    #   row 3 (all present)   -> complete
+    #   row 4 (a&c co-occur)  -> incomplete
+    mask = {
+        "a": [1, 0, 0, 0, 1],
+        "b": [1, 0, 1, 0, 0],
+        "c": [0, 0, 0, 0, 1],
+    }
+    out = missingness_overview(mask)
+    assert out["n_rows"] == 5
+    assert out["n_cols"] == 3
+    assert out["n_cols_with_null"] == 3
+    assert out["n_missing_cells"] == 5
+    assert out["missing_cell_pct"] == pytest.approx(33.33333333, abs=1e-6)
+    assert out["complete_rows"] == 2
+    assert out["incomplete_rows"] == 3
+    assert out["complete_pct"] == pytest.approx(40.0)
+    assert out["incomplete_pct"] == pytest.approx(60.0)
+
+
+def test_empty_dict_all_zero():
+    out = missingness_overview({})
+    assert out == {
+        "n_rows": 0,
+        "n_cols": 0,
+        "n_cols_with_null": 0,
+        "n_missing_cells": 0,
+        "missing_cell_pct": 0.0,
+        "complete_rows": 0,
+        "incomplete_rows": 0,
+        "complete_pct": 0.0,
+        "incomplete_pct": 0.0,
+    }
+
+
+def test_output_keys_contract():
+    # The 9-key contract holds even for the garbage/zero path.
+    assert set(missingness_overview({}).keys()) == EXPECTED_KEYS
+    assert set(missingness_overview({"a": [1, 0]}).keys()) == EXPECTED_KEYS
+
+
+def test_not_a_dict_returns_zero():
+    for bad in (None, [1, 0, 1], 42, "nope", 3.14):
+        out = missingness_overview(bad)
+        assert out["n_rows"] == 0
+        assert out["n_cols"] == 0
+        assert out["n_missing_cells"] == 0
+        assert out["missing_cell_pct"] == 0.0
+
+
+def test_no_nulls_all_complete():
+    mask = {"a": [0, 0, 0], "b": [0, 0, 0]}
+    out = missingness_overview(mask)
+    assert out["n_rows"] == 3
+    assert out["n_cols"] == 2
+    assert out["n_cols_with_null"] == 0
+    assert out["n_missing_cells"] == 0
+    assert out["missing_cell_pct"] == 0.0
+    assert out["complete_rows"] == 3
+    assert out["incomplete_rows"] == 0
+    assert out["complete_pct"] == pytest.approx(100.0)
+    assert out["incomplete_pct"] == pytest.approx(0.0)
+
+
+def test_none_values_treated_as_present():
+    # None and other non-1 values count as present (0).
+    mask = {"a": [None, 1, None, "x", 0]}
+    out = missingness_overview(mask)
+    assert out["n_rows"] == 5
+    assert out["n_cols"] == 1
+    assert out["n_missing_cells"] == 1  # only the explicit 1 at row 1
+    assert out["n_cols_with_null"] == 1
+    assert out["complete_rows"] == 4
+    assert out["incomplete_rows"] == 1
+
+
+def test_unequal_lengths_pad_with_max():
+    # Ragged lists: n_rows = max length; shorter column padded as present.
+    #   a = [1, 1] -> missing at rows 0, 1
+    #   b = [0]    -> row 1 padded to present
+    #   n_rows = 2, n_cols = 2, total_cells = 4, n_missing_cells = 2 -> 50%
+    mask = {"a": [1, 1], "b": [0]}
+    out = missingness_overview(mask)
+    assert out["n_rows"] == 2
+    assert out["n_cols"] == 2
+    assert out["n_cols_with_null"] == 1
+    assert out["n_missing_cells"] == 2
+    assert out["missing_cell_pct"] == pytest.approx(50.0)
+    assert out["complete_rows"] == 0
+    assert out["incomplete_rows"] == 2
+    assert out["incomplete_pct"] == pytest.approx(100.0)
+
+
+def test_columns_present_but_no_rows():
+    # Columns exist but all empty -> zero metrics, n_cols preserved.
+    out = missingness_overview({"a": [], "b": []})
+    assert out["n_rows"] == 0
+    assert out["n_cols"] == 2
+    assert out["n_missing_cells"] == 0
+    assert out["missing_cell_pct"] == 0.0
+    assert out["complete_pct"] == 0.0
+
+
+def test_never_raises_on_garbage():
+    # Non-list column values, mixed junk -> must not raise.
+    mask = {"a": "not a list", "b": 123, "c": [1, 0, 1]}
+    out = missingness_overview(mask)
+    assert set(out.keys()) == EXPECTED_KEYS
+    assert out["n_rows"] == 3
+    assert out["n_cols"] == 3
+    assert out["n_missing_cells"] == 2  # only col c contributes
+    assert out["n_cols_with_null"] == 1

python/functions/datascience/missingness_rank_bar_figure.md

@@ -0,0 +1,93 @@
+---
+id: missingness_rank_bar_figure_py_datascience
+name: missingness_rank_bar_figure
+kind: function
+lang: py
+domain: datascience
+version: "1.0.0"
+purity: impure
+signature: "def missingness_rank_bar_figure(names, pcts, title=\"% de valores faltantes por columna\") -> \"matplotlib.figure.Figure\""
+description: "Construye una figura matplotlib de barras horizontales que ordena las columnas de un dataset por su porcentaje de valores faltantes (0-100), la mayor arriba, etiquetando cada barra con su NN.N% al final. Usa ax.barh, eje X fijo 0-100 y labels truncados a ~22 chars. Devuelve un matplotlib.figure.Figure listo para rasterizar por el renderer del informe EDA (capítulo de datos faltantes). Backend Agg sin pyplot global; defensivo ante listas vacías, longitudes desiguales o valores no numéricos (nunca lanza)."
+tags: [eda, missing, missingness, ranking, bar, barh, matplotlib, figure, visualization, datascience, impure]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: [matplotlib]
+example: |
+  from datascience.missingness_rank_bar_figure import missingness_rank_bar_figure
+  names = ["edad", "ingresos", "ciudad", "email"]
+  pcts = [12.5, 40.0, 3.2, 0.0]
+  fig = missingness_rank_bar_figure(names, pcts, title="% de valores faltantes por columna")
+tested: true
+tests:
+  - "test_returns_figure_with_axes"
+  - "test_sorted_descending_largest_on_top"
+  - "test_empty_lists_do_not_raise_and_returns_figure"
+  - "test_xlim_is_zero_to_hundred"
+  - "test_length_mismatch_and_non_numeric_are_handled"
+test_file_path: "python/functions/datascience/missingness_rank_bar_figure_test.py"
+file_path: "python/functions/datascience/missingness_rank_bar_figure.py"
+params:
+  - name: names
+    desc: "Lista de nombres de columna. Puede venir vacía (devuelve figura \"sin datos faltantes\"). Los items se convierten a str y se truncan a ~22 chars con elipsis para las etiquetas del eje Y; los originales no se mutan."
+  - name: pcts
+    desc: "Lista paralela a names con el % de nulos en [0,100]. Valores None, NaN o no numéricos se coercen a 0.0 y los negativos se recortan a 0. Si len(names) != len(pcts) se recorta al menor de ambos para no romper."
+  - name: title
+    desc: "Título de la figura. Se trunca a ~60 chars con elipsis si es muy largo. Default \"% de valores faltantes por columna\"."
+output: "Un matplotlib.figure.Figure (figsize 6.4 x alto adaptativo según nº de barras, dpi 150) con un Axes de barras horizontales (ax.barh) ordenadas por % descendente, la mayor arriba. Eje X fijado a [0,100] con label \"% faltante\", etiquetas del eje Y truncadas a ~22 chars, y cada barra anotada con su NN.N% al final. Si names o pcts vienen vacíos devuelve una Figure con texto centrado \"sin datos faltantes\"; cualquier error inesperado se captura y devuelve una Figure con el mensaje de error (nunca lanza). El caller rasteriza/cierra la figura; la función no la muestra ni la guarda."
+---
+
+## Ejemplo
+
+```python
+from datascience.missingness_rank_bar_figure import missingness_rank_bar_figure
+
+# % de nulos por columna (p. ej. (df.isnull().mean() * 100).
+names = ["edad", "ingresos", "ciudad", "email"]
+pcts = [12.5, 40.0, 3.2, 0.0]
+
+fig = missingness_rank_bar_figure(
+    names,
+    pcts,
+    title="% de valores faltantes por columna",
+)
+
+# ingresos (40.0%) queda arriba; email (0.0%) abajo.
+# El renderer del informe lo rasteriza; aquí solo persistimos para inspección.
+fig.savefig("/tmp/missingness_rank.png")
+```
+
+## Cuando usarla
+
+Úsala al abrir el capítulo de datos faltantes de un informe EDA para responder
+"¿qué columnas están más incompletas?" de un vistazo. Pásale los nombres de
+columna y el % de nulos de cada una (`(df.isnull().mean() * 100).round(1)`); la
+función se encarga de ordenar de mayor a menor y poner la peor arriba. Es la
+pareja "magnitud" del heatmap de co-ocurrencia: las barras dicen *cuánto* falta
+en cada columna, el heatmap dice *si esas ausencias están relacionadas* entre
+columnas.
+
+## Gotchas
+
+- **Impura por matplotlib.** Toca la maquinaria de render. Usa el backend `Agg`
+  y la API orientada a objetos `Figure`/`add_subplot` — NUNCA `pyplot.*` aquí,
+  para no tocar el estado global ni filtrar figuras entre llamadas. `pyplot` NO
+  es thread-safe; esta función evita ese riesgo construyendo el `Figure`
+  directamente, así que es segura de llamar en bucle desde el renderer.
+- **El caller cierra la figura.** Devuelve el `Figure` pero no lo muestra ni lo
+  guarda. Quien la consume debe rasterizarla y luego liberarla
+  (`matplotlib.pyplot.close(fig)`) para no acumular memoria en lotes grandes.
+- **Espera porcentajes 0-100, no fracciones 0-1.** El eje X está fijado a
+  `[0, 100]`. Si pasas fracciones (`0.4` en vez de `40.0`) las barras saldrán
+  pegadas al origen. Multiplica por 100 antes de llamar.
+- **Alto adaptativo.** La altura de la figura crece con el número de barras
+  (hasta un tope) para que reports con muchas columnas sigan legibles; aun así,
+  conviene filtrar a las columnas con algún nulo antes de llamar para no listar
+  decenas de barras a 0%.
+- **Defensiva, nunca lanza.** Listas vacías, longitudes desiguales, valores
+  `None`/`NaN`/no numéricos o cualquier error inesperado se manejan sin propagar:
+  en el peor caso devuelve una `Figure` con "sin datos faltantes" o con el texto
+  del error. No envuelvas la llamada en try/except por miedo a un raise — no lo
+  hay.

python/functions/datascience/missingness_rank_bar_figure.py

@@ -0,0 +1,150 @@
+"""Impure EDA helper: ranked bar figure of missing-value share (`eda` group).
+
+Builds a horizontal bar chart ranking the columns of a dataset by their
+percentage of missing values (0-100), largest at the top, each bar labelled with
+its ``NN.N%`` at the end. Returns a ready-to-rasterize
+``matplotlib.figure.Figure``; it never shows nor saves it.
+
+Impure because it touches matplotlib's rendering machinery. It uses the headless
+Agg backend and the object-oriented ``Figure`` API (no ``pyplot``) so it leaks no
+global state and is safe to call repeatedly from a report renderer.
+"""
+
+import matplotlib
+
+matplotlib.use("Agg")
+
+from matplotlib.figure import Figure  # noqa: E402
+
+# Muted gray for secondary text (no-data / fallback messages).
+_MUTED_TEXT = "#5f6b7a"
+# Soft red for the error fallback message.
+_ERROR_TEXT = "#b00020"
+# Bar fill — a calm blue that reads well on white at report size.
+_BAR_COLOR = "#4C72B0"
+
+
+def _truncate(text, width: int = 22) -> str:
+    """Truncate ``text`` to ``width`` chars, appending an ellipsis if cut."""
+    s = "" if text is None else str(text)
+    if len(s) <= width:
+        return s
+    if width <= 1:
+        return s[:width]
+    return s[: width - 1] + "…"
+
+
+def _message_figure(message: str, color: str = _MUTED_TEXT) -> "Figure":
+    """Return a fallback ``Figure`` carrying a single centered message."""
+    fig = Figure(figsize=(6.4, 4.0), dpi=150)
+    ax = fig.add_subplot(111)
+    ax.axis("off")
+    ax.text(
+        0.5,
+        0.5,
+        message,
+        ha="center",
+        va="center",
+        fontsize=12,
+        color=color,
+        wrap=True,
+        transform=ax.transAxes,
+    )
+    fig.tight_layout()
+    return fig
+
+
+def missingness_rank_bar_figure(
+    names,
+    pcts,
+    title: str = "% de valores faltantes por columna",
+) -> "matplotlib.figure.Figure":
+    """Build a horizontal ranked bar figure of missing-value share per column.
+
+    Pairs each column name with its missing percentage, sorts by percentage
+    descending and draws horizontal bars with the largest at the top. The X axis
+    is pinned to ``[0, 100]`` so bars are comparable across reports, each bar is
+    annotated with its ``NN.N%`` at the end, and the Y tick labels are truncated
+    to ~22 chars.
+
+    The function is fully defensive: empty/mismatched/non-numeric input never
+    raises. When there is nothing valid to draw it returns a ``Figure`` carrying
+    a centered "sin datos faltantes" message, and any unexpected error is caught
+    and turned into a fallback ``Figure`` carrying the error text.
+
+    Args:
+        names: List of column names. May be empty. Items are stringified and
+            truncated for display; the originals are not mutated.
+        pcts: List parallel to ``names`` of missing-value percentages in
+            ``[0, 100]``. Non-numeric/``None`` values are coerced to ``0.0`` and
+            negatives are clamped to ``0``. The list is truncated to
+            ``min(len(names), len(pcts))`` so a length mismatch never crashes.
+        title: Figure title. Default "% de valores faltantes por columna".
+
+    Returns:
+        A ``matplotlib.figure.Figure`` with a single horizontal-bar Axes. The
+        caller is responsible for rasterizing/closing it.
+    """
+    try:
+        if (
+            not isinstance(names, (list, tuple))
+            or not isinstance(pcts, (list, tuple))
+            or len(names) == 0
+            or len(pcts) == 0
+        ):
+            return _message_figure("sin datos faltantes")
+
+        # --- Pair names with coerced percentages, tolerating length mismatch.
+        pairs = []
+        for name, pct in zip(names, pcts):
+            try:
+                val = float(pct)
+            except (TypeError, ValueError):
+                val = 0.0
+            if val != val:  # NaN guard.
+                val = 0.0
+            val = max(0.0, val)
+            pairs.append((name, val))
+
+        if not pairs:
+            return _message_figure("sin datos faltantes")
+
+        # Sort by percentage descending; barh draws bottom-up, so the largest
+        # ends at the top when we reverse the order before plotting.
+        pairs.sort(key=lambda p: p[1], reverse=True)
+        ordered = list(reversed(pairs))  # smallest first -> largest on top.
+
+        labels = [_truncate(name, 22) for name, _ in ordered]
+        values = [val for _, val in ordered]
+        y_pos = range(len(ordered))
+
+        # Height scales with the number of bars so dense reports stay readable.
+        height = max(2.4, min(0.4 * len(ordered) + 1.2, 14.0))
+        fig = Figure(figsize=(6.4, height), dpi=150)
+        ax = fig.add_subplot(111)
+
+        ax.barh(list(y_pos), values, color=_BAR_COLOR, edgecolor="white")
+        ax.set_yticks(list(y_pos))
+        ax.set_yticklabels(labels, fontsize=8)
+        ax.set_xlim(0, 100)
+        ax.set_xlabel("% faltante", fontsize=9)
+
+        # Annotate each bar with its percentage at the end of the bar.
+        for y, val in zip(y_pos, values):
+            ax.text(
+                min(val + 1.5, 99.0),
+                y,
+                f"{val:.1f}%",
+                va="center",
+                ha="left" if val < 90 else "right",
+                fontsize=7,
+                color="#202020",
+            )
+
+        if title:
+            ax.set_title(_truncate(title, 60), fontsize=12, loc="left", pad=10)
+
+        fig.tight_layout()
+        return fig
+    except Exception as exc:  # noqa: BLE001 — never raise from a figure builder.
+        return _message_figure(f"error al dibujar barras: {exc}", color=_ERROR_TEXT)

python/functions/datascience/missingness_rank_bar_figure_test.py

@@ -0,0 +1,64 @@
+"""Tests para missingness_rank_bar_figure (barras de % faltante, grupo eda).
+
+Usa el backend Agg sin pyplot; no muestra ni guarda figuras. Cada test cierra
+explícitamente la Figure construida (matplotlib.pyplot.close) para no acumular
+estado entre tests.
+"""
+
+import matplotlib
+
+matplotlib.use("Agg")
+
+import matplotlib.pyplot as plt  # noqa: E402
+from matplotlib.figure import Figure  # noqa: E402
+
+from missingness_rank_bar_figure import missingness_rank_bar_figure
+
+
+def test_returns_figure_with_axes():
+    names = ["edad", "ingresos", "ciudad"]
+    pcts = [12.5, 40.0, 3.2]
+    fig = missingness_rank_bar_figure(names, pcts, title="faltantes")
+    assert isinstance(fig, Figure)
+    assert len(fig.axes) >= 1
+    plt.close(fig)
+
+
+def test_sorted_descending_largest_on_top():
+    names = ["a", "b", "c"]
+    pcts = [10.0, 50.0, 25.0]
+    fig = missingness_rank_bar_figure(names, pcts)
+    ax = fig.axes[0]
+    # barh dibuja de abajo arriba; la mayor (50, "b") debe quedar arriba (mayor y).
+    bars = ax.patches
+    # El último parche (mayor índice y) corresponde a la barra superior.
+    widths = [b.get_width() for b in bars]
+    assert max(widths) == 50.0
+    # La barra con la mayor anchura es la de mayor coordenada y (arriba).
+    top_bar = max(bars, key=lambda b: b.get_y())
+    assert top_bar.get_width() == 50.0
+    plt.close(fig)
+
+
+def test_empty_lists_do_not_raise_and_returns_figure():
+    fig = missingness_rank_bar_figure([], [], title="vacía")
+    assert isinstance(fig, Figure)
+    assert len(fig.axes) >= 1
+    plt.close(fig)
+
+
+def test_xlim_is_zero_to_hundred():
+    fig = missingness_rank_bar_figure(["a"], [42.0])
+    ax = fig.axes[0]
+    assert ax.get_xlim() == (0.0, 100.0)
+    plt.close(fig)
+
+
+def test_length_mismatch_and_non_numeric_are_handled():
+    # Más names que pcts + un pct None -> zip recorta y None se coacciona a 0.
+    names = ["a", "b", "c"]
+    pcts = [None, 30.0]
+    fig = missingness_rank_bar_figure(names, pcts)
+    assert isinstance(fig, Figure)
+    assert len(fig.axes) >= 1
+    plt.close(fig)

python/functions/datascience/missingness_row_patterns.md

@@ -0,0 +1,65 @@
+---
+name: missingness_row_patterns
+kind: function
+lang: py
+domain: datascience
+version: "1.0.0"
+purity: pure
+signature: "def missingness_row_patterns(null_mask, top_n=10) -> dict"
+description: "Agrupa las filas de un dataset por su patron de ausencias (estilo matriz de missingno): para cada fila, el patron es la tupla ORDENADA de columnas que faltan en esa fila (las que tienen 1 en el null_mask). Cuenta la frecuencia de cada patron distinto, incluido el patron vacio (fila completa). Devuelve el top_n por frecuencia con su pct sobre el total. Pura, lectura defensiva, NUNCA lanza; {} -> n_rows 0."
+tags: [eda, missingness, missingno, patterns, profiling, datascience, data-quality]
+params:
+  - name: null_mask
+    desc: "Dict {col: [0/1, ...]} alineado por fila, donde 1 = la celda falta en esa fila y 0 = presente. Todas las columnas deberian tener la misma longitud (una entrada por fila); si difieren, n_rows es la lista mas larga y las celdas fuera de rango cuentan como presentes. Las claves se ordenan por str(col) para canonizar el patron. {} (o no-dict) -> n_rows 0."
+  - name: top_n
+    desc: "Maximo de patrones devueltos en `patterns`, rankeados por n_rows desc (desempate: menos columnas primero, luego nombres de columna). El recuento total de patrones distintos siempre se reporta en `n_patterns`, no se trunca. Default 10. Valores negativos -> 0; no-int -> 10."
+output: "Dict {n_rows: int (filas totales), n_patterns: int (patrones distintos, incluye el patron vacio = fila completa), complete_rows: int (filas con patron vacio, nada falta), patterns: lista del top_n ordenada por n_rows desc con [{missing_cols: [col,...] (vacio = fila completa), n_rows: int, pct: float 0-100 sobre n_rows total, redondeado a 2 decimales}]}. Para {} devuelve n_rows 0 y patterns []. NUNCA lanza."
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: ""
+imports: []
+tested: true
+tests: ["test_patron_dominante_completas_singleton", "test_mask_vacio", "test_top_n_trunca_pero_cuenta_todos"]
+test_file_path: "python/functions/datascience/missingness_row_patterns_test.py"
+file_path: "python/functions/datascience/missingness_row_patterns.py"
+---
+
+## Ejemplo
+
+```python
+import sys, os
+sys.path.insert(0, os.path.join("python", "functions"))
+from datascience.missingness_row_patterns import missingness_row_patterns
+
+# null_mask alineado por fila: 1 = la celda falta en esa fila.
+null_mask = {
+    "A": [1, 1, 1, 1, 0, 0, 0, 0, 0, 0],
+    "B": [1, 1, 1, 1, 0, 0, 0, 0, 0, 0],
+    "C": [0, 0, 0, 0, 0, 0, 0, 0, 0, 1],
+}
+out = missingness_row_patterns(null_mask, top_n=10)
+print(out["n_rows"], out["n_patterns"], out["complete_rows"])  # 10 3 5
+for p in out["patterns"]:
+    label = p["missing_cols"] or "(fila completa)"
+    print(label, p["n_rows"], p["pct"])
+# (fila completa) 5 50.0
+# ['A', 'B'] 4 40.0
+# ['C'] 1 10.0
+```
+
+## Cuando usarla
+
+- Usala en el capitulo de calidad/ausencias de `AutomaticEDA` para mostrar la "matriz de patrones de missingno": en vez de pintar celda a celda, resume que combinaciones de columnas se quedan en blanco juntas y con que frecuencia.
+- Cuando ya tengas el null_mask por columna (1=falta) y quieras detectar co-ausencia estructural ("A y B siempre faltan juntas") antes de decidir una imputacion o un drop conjunto de columnas.
+- Cuando necesites una tabla compacta "patron -> nº filas -> pct" para un report o un grafico de barras de los patrones de ausencia mas comunes, separando ademas cuantas filas estan completas (`complete_rows`).
+
+## Gotchas
+
+- Funcion pura, sin I/O y determinista. Lectura defensiva: `{}` o un no-dict devuelven `n_rows` 0 con `patterns` []. NUNCA lanza.
+- El patron vacio (fila completa, `missing_cols=[]`) SI cuenta como patron: aparece en `n_patterns` y puede aparecer en `patterns`. El consumidor lo etiqueta como "(fila completa)".
+- `pct` es sobre `n_rows` total (0-100), redondeado a 2 decimales. La suma de los `pct` de TODOS los patrones es 100; si `top_n` trunca, los `pct` mostrados sumaran menos.
+- Las columnas se ordenan por `str(col)` para canonizar cada patron, asi `{A,B}` y `{B,A}` colapsan al mismo patron `["A", "B"]`.
+- Una celda cuenta como ausente solo si vale 1 (`int(cell) == 1`); 0, None y valores no numericos se tratan como presentes.
+- Si las listas de columnas tienen longitudes distintas, `n_rows` es la mas larga y las posiciones fuera de rango de una columna corta cuentan como presentes (0).

python/functions/datascience/missingness_row_patterns.py

@@ -0,0 +1,107 @@
+"""missingness_row_patterns — distinct per-row missingness patterns (missingno matrix style).
+
+Pure function: no I/O, deterministic, NEVER raises. Given a per-column null mask
+aligned by row ({col: [0/1, ...]}, 1 = missing), it groups rows by their missing
+"pattern" — the sorted tuple of column names that are missing in that row — and
+counts how often each distinct pattern occurs.
+
+This mirrors the missingno matrix idea: instead of plotting per-cell nullity, it
+collapses each row to the SET of columns it lacks, surfacing co-missing structure
+(e.g. "A and B always go missing together"). The empty pattern (a fully complete
+row) is a first-class pattern and may appear in the result with missing_cols=[];
+the caller labels it "(fila completa)".
+"""
+
+
+def _is_missing(cell) -> bool:
+    """A cell counts as missing when it equals 1 (truthy 0/1 mask).
+
+    None / 0 / non-numeric are treated as present. Defensive: never raises.
+    """
+    try:
+        return int(cell) == 1
+    except (TypeError, ValueError):
+        return bool(cell)
+
+
+def missingness_row_patterns(null_mask, top_n=10) -> dict:
+    """Count distinct per-row missingness patterns from a column null mask.
+
+    For each row, its pattern is the sorted tuple of column names missing in that
+    row (the columns whose value is 1). The frequency of each distinct pattern is
+    counted, including the empty pattern (a complete row with nothing missing).
+
+    Args:
+        null_mask: Dict {col: [0/1, ...]} aligned by row, where 1 means the cell
+            is missing in that row. Read defensively; columns with differing
+            lengths are tolerated (n_rows is the longest list; out-of-range cells
+            count as present). Empty dict -> n_rows 0.
+        top_n: Maximum number of patterns returned in `patterns`, ranked by
+            n_rows desc (tiebreak: fewer columns first, then column names). The
+            full count of distinct patterns is always reported in `n_patterns`.
+
+    Returns:
+        Dict:
+        {
+          "n_rows": int,            # total rows
+          "n_patterns": int,        # distinct patterns (incl. the empty pattern)
+          "complete_rows": int,     # rows with the empty pattern (nothing missing)
+          "patterns": [             # top_n patterns, n_rows desc
+             {"missing_cols": [col, ...], "n_rows": int, "pct": float}  # [] = complete row
+          ],
+        }
+        For {} (or a non-dict) returns n_rows 0 and patterns []. NEVER raises.
+    """
+    empty = {"n_rows": 0, "n_patterns": 0, "complete_rows": 0, "patterns": []}
+    if not isinstance(null_mask, dict) or not null_mask:
+        return empty
+
+    # Stable, canonical column order so each row's pattern tuple is sorted.
+    items = sorted(null_mask.items(), key=lambda kv: str(kv[0]))
+    names = [str(k) for k, _ in items]
+    lists = [v if isinstance(v, (list, tuple)) else [] for _, v in items]
+
+    n_rows = max((len(lst) for lst in lists), default=0)
+    if n_rows == 0:
+        return empty
+
+    # Defensive parsing of top_n.
+    try:
+        limit = int(top_n)
+    except (TypeError, ValueError):
+        limit = 10
+    if limit < 0:
+        limit = 0
+
+    counts: dict = {}
+    n_cols = len(names)
+    for r in range(n_rows):
+        # names is sorted, so iterating in order yields an already-sorted tuple.
+        pattern = tuple(
+            names[c]
+            for c in range(n_cols)
+            if r < len(lists[c]) and _is_missing(lists[c][r])
+        )
+        counts[pattern] = counts.get(pattern, 0) + 1
+
+    complete_rows = counts.get((), 0)
+    n_patterns = len(counts)
+
+    # Rank: n_rows desc, then fewer columns first, then column names (deterministic).
+    ordered = sorted(counts.items(), key=lambda kv: (-kv[1], len(kv[0]), kv[0]))
+
+    patterns = [
+        {
+            "missing_cols": list(pat),
+            "n_rows": cnt,
+            "pct": round(100.0 * cnt / n_rows, 2),
+        }
+        for pat, cnt in ordered[:limit]
+    ]
+
+    return {
+        "n_rows": n_rows,
+        "n_patterns": n_patterns,
+        "complete_rows": complete_rows,
+        "patterns": patterns,
+    }

python/functions/datascience/missingness_row_patterns_test.py

@@ -0,0 +1,87 @@
+"""Tests para missingness_row_patterns."""
+
+import os
+import sys
+
+sys.path.insert(0, os.path.dirname(__file__))
+
+from missingness_row_patterns import missingness_row_patterns
+
+_EXPECTED_KEYS = {"n_rows", "n_patterns", "complete_rows", "patterns"}
+
+
+def test_patron_dominante_completas_singleton():
+    """Golden: {A,B} co-faltan en 4 filas + 5 filas completas + 1 singleton {C}."""
+    # 10 filas. A y B faltan juntas en las filas 0-3; filas 4-8 completas;
+    # la fila 9 solo le falta C.
+    null_mask = {
+        "A": [1, 1, 1, 1, 0, 0, 0, 0, 0, 0],
+        "B": [1, 1, 1, 1, 0, 0, 0, 0, 0, 0],
+        "C": [0, 0, 0, 0, 0, 0, 0, 0, 0, 1],
+    }
+    out = missingness_row_patterns(null_mask)
+
+    assert set(out.keys()) == _EXPECTED_KEYS
+    assert out["n_rows"] == 10
+    # 3 patrones distintos: (A,B), () y (C,).
+    assert out["n_patterns"] == 3
+    # 5 filas completas (filas 4-8).
+    assert out["complete_rows"] == 5
+
+    # Orden: n_rows desc; desempate menos columnas primero.
+    # () tiene 5 filas, (A,B) 4, (C,) 1.
+    pats = out["patterns"]
+    assert len(pats) == 3
+
+    assert pats[0]["missing_cols"] == []
+    assert pats[0]["n_rows"] == 5
+    assert pats[0]["pct"] == 50.0
+
+    assert pats[1]["missing_cols"] == ["A", "B"]
+    assert pats[1]["n_rows"] == 4
+    assert pats[1]["pct"] == 40.0
+
+    assert pats[2]["missing_cols"] == ["C"]
+    assert pats[2]["n_rows"] == 1
+    assert pats[2]["pct"] == 10.0
+
+    # Tipos de salida.
+    assert isinstance(out["n_rows"], int)
+    assert isinstance(pats[0]["pct"], float)
+
+
+def test_mask_vacio():
+    """{} -> n_rows 0, sin patrones, nunca lanza."""
+    out = missingness_row_patterns({})
+    assert out == {
+        "n_rows": 0,
+        "n_patterns": 0,
+        "complete_rows": 0,
+        "patterns": [],
+    }
+    # No dict / None tambien degradan a vacio sin lanzar.
+    assert missingness_row_patterns(None)["n_rows"] == 0
+    # Columnas presentes pero listas vacias -> n_rows 0.
+    assert missingness_row_patterns({"A": [], "B": []})["patterns"] == []
+
+
+def test_top_n_trunca_pero_cuenta_todos():
+    """top_n limita `patterns`, pero n_patterns reporta TODOS los distintos."""
+    null_mask = {
+        "A": [0, 1, 1, 0, 1],
+        "B": [0, 0, 0, 1, 1],
+        "C": [0, 0, 0, 0, 1],
+    }
+    # Filas: ()  (A,)  (A,)  (B,)  (A,B,C)
+    out = missingness_row_patterns(null_mask, top_n=2)
+
+    assert out["n_rows"] == 5
+    assert out["n_patterns"] == 4          # (), (A,), (B,), (A,B,C)
+    assert out["complete_rows"] == 1
+    # Solo 2 patrones devueltos pese a haber 4.
+    assert len(out["patterns"]) == 2
+    # (A,) domina con 2 filas; desempate del 2o entre los de 1 fila -> () (0 cols).
+    assert out["patterns"][0]["missing_cols"] == ["A"]
+    assert out["patterns"][0]["n_rows"] == 2
+    assert out["patterns"][1]["missing_cols"] == []
+    assert out["patterns"][1]["n_rows"] == 1

python/functions/datascience/relationship_scatter_figure.md

@@ -0,0 +1,122 @@
+---
+id: relationship_scatter_figure_py_datascience
+name: relationship_scatter_figure
+kind: function
+lang: py
+domain: datascience
+version: "1.0.0"
+purity: impure
+signature: "def relationship_scatter_figure(xs: list, ys: list, x_label: str = \"\", y_label: str = \"\", classification: dict = None, max_points: int = 2000) -> \"matplotlib.figure.Figure\""
+description: "Construye una figura matplotlib scatter de un par de variables numéricas con su curva/recta de ajuste y una anotación del tipo de relación (lineal, polinómica grado 2/3, monótona no-lineal, etc.) más sus métricas (r, ρ, R²lin, R²poly). Consume el dict de classify_relationship_type; si es None lo calcula internamente reusando esa función. Devuelve un matplotlib.figure.Figure listo para rasterizar por el renderer del informe EDA (PDF/PPTX). Backend Agg sin pyplot global; downsample determinista de los puntos dibujados; defensivo ante vacío/None."
+tags: [eda, correlation, scatter, relationship, matplotlib, figure, visualization, datascience, impure]
+uses_functions: [classify_relationship_type_py_datascience]
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: [matplotlib, numpy]
+example: |
+  from relationship_scatter_figure import relationship_scatter_figure
+  xs = [float(i) for i in range(100)]
+  ys = [0.5 * x * x - x + 3 for x in xs]
+  classification = {
+      "tipo": "polinómica (grado 2)", "pearson": 0.97, "spearman": 0.99,
+      "r2_linear": 0.92, "r2_poly2": 0.999, "r2_poly3": 0.999,
+      "best_degree": 2, "coeffs": [0.5, -1.0, 3.0],
+  }
+  fig = relationship_scatter_figure(xs, ys, x_label="dosis", y_label="efecto", classification=classification)
+tested: true
+tests:
+  - "test_returns_figure"
+  - "test_downsample_determinista"
+  - "test_empty_no_lanza"
+  - "test_classification_none"
+test_file_path: "python/functions/datascience/relationship_scatter_figure_test.py"
+file_path: "python/functions/datascience/relationship_scatter_figure.py"
+params:
+  - name: xs
+    desc: "Lista (o tupla) de valores x. Se emparejan por índice con ys. Valores None, bool, NaN o inf descartan ese par (lectura defensiva)."
+  - name: ys
+    desc: "Lista (o tupla) de valores y, paralela a xs. Mismas reglas defensivas que xs."
+  - name: x_label
+    desc: "Etiqueta del eje/título para la variable x. Default \"\" (en el título cae a \"x\")."
+  - name: y_label
+    desc: "Etiqueta del eje/título para la variable y. Default \"\" (en el título cae a \"y\")."
+  - name: classification
+    desc: "Opcional. Dict de classify_relationship_type con claves tipo, pearson, r2_linear, spearman, r2_poly2, r2_poly3, best_degree, coeffs. Si es None se calcula internamente importando y llamando a classify_relationship_type sobre los pares limpios (self-contained). Si el módulo hermano no está disponible, se dibuja el scatter sin curva de ajuste ni anotación. Default None."
+  - name: max_points
+    desc: "Tope del nº de puntos DIBUJADOS. Si los pares limpios superan el tope, la nube se submuestrea por paso fijo ceil(n/max_points) tomando pairs[::step] — DETERMINISTA, no aleatorio, reproducible. La clasificación/ajuste usa SIEMPRE todos los pares limpios; el downsample solo adelgaza el dibujo. Valor no-positivo o no-int desactiva el downsample. Default 2000."
+output: "Un matplotlib.figure.Figure (figsize 6.4x4.0, dpi 150) con un Axes scatter (puntos semitransparentes alpha 0.5, color #4C72B0), la curva/recta de ajuste (numpy.polyval sobre coeffs, color #C44E52) cuando hay un ajuste polinómico disponible, título \"{x_label} ↔ {y_label}\", labels de ejes y una caja de anotación en la esquina superior izquierda con el tipo de relación y las métricas disponibles (r, ρ, R²lin, R²poly; se omiten las None). Si tras la limpieza hay menos de 2 pares válidos, devuelve igualmente una Figure con un texto centrado \"Sin datos suficientes para el scatter\" (nunca lanza). El caller rasteriza/cierra la figura; la función no la muestra ni la guarda."
+---
+
+## Ejemplo
+
+```python
+from relationship_scatter_figure import relationship_scatter_figure
+
+# Par numérico con relación cuadrática y su clasificación (de
+# classify_relationship_type). Pasándola explícita evitas recomputarla.
+xs = [float(i) for i in range(100)]
+ys = [0.5 * x * x - x + 3 for x in xs]
+classification = {
+    "tipo": "polinómica (grado 2)",
+    "pearson": 0.97,
+    "spearman": 0.99,
+    "r2_linear": 0.92,
+    "r2_poly2": 0.999,
+    "r2_poly3": 0.999,
+    "best_degree": 2,
+    "coeffs": [0.5, -1.0, 3.0],
+}
+
+fig = relationship_scatter_figure(
+    xs, ys, x_label="dosis", y_label="efecto", classification=classification
+)
+
+# El renderer del informe lo rasteriza; aquí solo persistimos para inspección.
+fig.savefig("/tmp/scatter_dosis_efecto.png")
+
+# Con classification=None la función la calcula internamente (self-contained):
+fig2 = relationship_scatter_figure(xs, ys, x_label="dosis", y_label="efecto")
+```
+
+## Cuando usarla
+
+Úsala dentro del informe EDA automático cuando quieras visualizar de un vistazo
+la relación entre dos variables numéricas: la nube de puntos, la curva que mejor
+la ajusta y una etiqueta legible del tipo de relación con sus métricas. Es la
+pareja "vista humana" de `classify_relationship_type`: esa función decide el
+tipo y los coeficientes; esta los pinta en una `Figure` que el renderer del
+informe rasteriza a PDF/PPTX. Pásale el dict de clasificación si ya lo tienes
+calculado (evitas recomputar el ajuste); si no, déjalo en `None` y la función lo
+resuelve sola sobre los pares limpios. Pensada para móvil: anotación pequeña
+(fontsize 8) y nube adelgazada por `max_points` para que el PDF no pese.
+
+## Gotchas
+
+- **Impura por matplotlib.** Toca la maquinaria de render. Usa el backend `Agg`
+  y la API orientada a objetos `Figure`/`add_subplot` — NUNCA `pyplot.*` aquí,
+  para no tocar el estado global ni filtrar figuras entre llamadas. `pyplot` NO
+  es thread-safe; esta función lo evita construyendo el `Figure` directamente,
+  así que es segura de llamar en bucle desde el renderer.
+- **El caller cierra la figura.** Devuelve el `Figure` pero no lo muestra ni lo
+  guarda. Quien la consume debe rasterizarla y luego liberarla
+  (`matplotlib.pyplot.close(fig)`) para no acumular memoria en lotes grandes de
+  pares de columnas.
+- **Downsample determinista, solo del dibujo.** Cuando los pares limpios superan
+  `max_points`, la nube DIBUJADA se adelgaza por paso fijo `pairs[::step]`
+  (reproducible, no aleatorio). La clasificación y el ajuste usan SIEMPRE todos
+  los pares limpios; el downsample no altera las métricas ni la curva.
+- **`classification=None` ⇒ se calcula sola.** Importa y llama a
+  `classify_relationship_type` sobre los pares limpios. Si ese módulo hermano no
+  está disponible (entorno incompleto), NO lanza: dibuja el scatter sin curva de
+  ajuste ni anotación. Pasar la clasificación explícita es más barato (no
+  recomputa el ajuste).
+- **Sin curva para `monótona no-lineal`.** Cuando `coeffs` es `None` o
+  `best_degree` es `None` (p.ej. tipo "monótona no-lineal"), no se pinta recta
+  polinómica — solo la nube y la anotación. Tampoco se dibuja la curva si el
+  rango de x es nulo (todos los x iguales). Nunca falla por esto.
+- **Defensiva, nunca lanza.** `xs=[]`, `ys=[]`, menos de 2 pares válidos, ends
+  `None`/`bool`/`NaN`/`inf` o `coeffs` malformado se manejan sin error: en el
+  peor caso devuelve una `Figure` con "Sin datos suficientes para el scatter".
+  No envuelvas la llamada en try/except por miedo a un raise — no lo hay.

python/functions/datascience/relationship_scatter_figure.py

@@ -0,0 +1,322 @@
+"""Impure EDA helper: scatter figure of a numeric pair with its fit (`eda` group).
+
+Builds a matplotlib scatter of two numeric variables, overlays the fitted
+curve/line implied by the relationship classification (linear, polynomial of
+degree 2/3, etc.) and annotates the relationship type with its available
+metrics. Returns a ready-to-rasterize ``matplotlib.figure.Figure``; it never
+shows nor saves it.
+
+Impure because it touches matplotlib's rendering machinery. It uses the headless
+Agg backend and the object-oriented ``Figure`` API (no ``pyplot``) so it leaks no
+global state and is safe to call repeatedly from a report renderer.
+
+To keep the rendered PDF/PPTX light on phones, when the number of valid pairs
+exceeds ``max_points`` the *plotted* points are down-sampled DETERMINISTICALLY by
+a fixed step (``pairs[::step]``), never randomly, so the output is reproducible.
+The classification/fit always uses every clean pair; the down-sample only thins
+the drawn cloud.
+"""
+
+import math
+
+import matplotlib
+
+matplotlib.use("Agg")
+
+import numpy as np  # noqa: E402
+from matplotlib.figure import Figure  # noqa: E402
+
+# Sober blue for the scatter cloud and red for the fitted curve (Tufte: the
+# data points are the primary ink, the fit is the secondary highlight).
+_POINT_COLOR = "#4C72B0"
+_FIT_COLOR = "#C44E52"
+# Muted gray for the no-data fallback message.
+_MUTED_TEXT = "#5f6b7a"
+
+
+def _finite(value):
+    """Coerce ``value`` to a finite float, or return None when not usable.
+
+    bool is a subclass of int, but a real numeric measurement is never a bool,
+    so True/False are treated as missing instead of coercing to 1.0/0.0. NaN and
+    +/-infinity are never valid either.
+    """
+    if value is None or isinstance(value, bool):
+        return None
+    try:
+        f = float(value)
+    except (TypeError, ValueError):
+        return None
+    if math.isnan(f) or math.isinf(f):
+        return None
+    return f
+
+
+def _clean_pairs(xs, ys):
+    """Pair ``xs[i], ys[i]`` by index, dropping any pair with a non-finite end."""
+    pairs = []
+    if isinstance(xs, (list, tuple)) and isinstance(ys, (list, tuple)):
+        n = min(len(xs), len(ys))
+        for i in range(n):
+            x = _finite(xs[i])
+            y = _finite(ys[i])
+            if x is None or y is None:
+                continue
+            pairs.append((x, y))
+    return pairs
+
+
+def _ordered_trend(xs_clean, ys_clean, n_bins: int = 12):
+    """Return (x_trend, y_trend): the ordered trend of y over x for a monotonic
+    relationship that has no polynomial fit.
+
+    When x has few distinct values (an ordinal/discrete scale) the trend is the
+    mean of y per distinct x value. Otherwise x is split into ``n_bins`` ordered
+    quantile bins and each point is (mean x, mean y) of the bin. Returns
+    ``(None, None)`` when there is nothing meaningful to draw.
+    """
+    x_arr = np.asarray(xs_clean, dtype=float)
+    y_arr = np.asarray(ys_clean, dtype=float)
+    if x_arr.size < 2:
+        return None, None
+    uniq = np.unique(x_arr)
+    if uniq.size <= max(2, n_bins):
+        # Discrete x: one trend point per distinct value (mean y).
+        xt = uniq
+        yt = np.array([float(np.mean(y_arr[x_arr == ux])) for ux in uniq])
+        return xt, yt
+    # Continuous x: ordered quantile bins, (mean x, mean y) per bin.
+    order = np.argsort(x_arr, kind="stable")
+    x_sorted = x_arr[order]
+    y_sorted = y_arr[order]
+    chunks_x = np.array_split(x_sorted, n_bins)
+    chunks_y = np.array_split(y_sorted, n_bins)
+    xt = np.array([float(np.mean(cx)) for cx in chunks_x if cx.size])
+    yt = np.array([float(np.mean(cy)) for cy in chunks_y if cy.size])
+    return xt, yt
+
+
+def _no_data_figure(message: str) -> "matplotlib.figure.Figure":
+    """A bare Figure carrying a centered muted message (defensive fallback)."""
+    fig = Figure(figsize=(6.4, 4.0), dpi=150)
+    ax = fig.add_subplot(111)
+    ax.axis("off")
+    ax.text(
+        0.5,
+        0.5,
+        message,
+        ha="center",
+        va="center",
+        fontsize=12,
+        color=_MUTED_TEXT,
+        transform=ax.transAxes,
+    )
+    fig.tight_layout()
+    return fig
+
+
+def _metrics_caption(classification: dict) -> str:
+    """Format the available metrics of a classification dict into one line.
+
+    Omits the metrics that are None. Keys consumed (any may be absent/None):
+    ``pearson`` (r), ``spearman`` (rho), ``r2_linear`` (R²lin) and the best
+    polynomial R² (``r2_poly3`` if a cubic was the best fit, else ``r2_poly2``).
+    """
+    parts = []
+    r = _finite(classification.get("pearson"))
+    if r is not None:
+        parts.append(f"r={r:.2f}")
+    rho = _finite(classification.get("spearman"))
+    if rho is not None:
+        parts.append(f"ρ={rho:.2f}")
+    r2_lin = _finite(classification.get("r2_linear"))
+    if r2_lin is not None:
+        parts.append(f"R²lin={r2_lin:.2f}")
+    # Prefer the R² of the best polynomial degree when it is a poly fit.
+    best_degree = classification.get("best_degree")
+    r2_poly = None
+    if best_degree == 3:
+        r2_poly = _finite(classification.get("r2_poly3"))
+    elif best_degree == 2:
+        r2_poly = _finite(classification.get("r2_poly2"))
+    if r2_poly is None:
+        # Fall back to whichever poly R² is present (cubic first).
+        r2_poly = _finite(classification.get("r2_poly3"))
+        if r2_poly is None:
+            r2_poly = _finite(classification.get("r2_poly2"))
+    if r2_poly is not None:
+        parts.append(f"R²poly={r2_poly:.2f}")
+    return "  ".join(parts)
+
+
+def relationship_scatter_figure(
+    xs: list,
+    ys: list,
+    x_label: str = "",
+    y_label: str = "",
+    classification: dict = None,
+    max_points: int = 2000,
+) -> "matplotlib.figure.Figure":
+    """Build a scatter figure of a numeric pair with its fit and a type label.
+
+    Cleans the pairs defensively (drops any pair with a None/bool/NaN/inf end),
+    plots a semi-transparent scatter cloud (down-sampled deterministically when
+    it exceeds ``max_points``), overlays the polynomial fit implied by
+    ``classification`` and annotates the relationship type plus its available
+    metrics in a corner box.
+
+    The fit and classification always use every clean pair; only the drawn cloud
+    is thinned by the down-sample. When ``classification`` is None it is computed
+    internally by reusing ``classify_relationship_type`` over the clean pairs, so
+    the function is self-contained.
+
+    The function is fully defensive: empty input, fewer than 2 clean pairs, a
+    missing/None ``coeffs`` or a missing sibling classifier never raise. When
+    there is nothing valid to draw it still returns a ``Figure`` carrying a
+    centered "Sin datos suficientes para el scatter" message.
+
+    Args:
+        xs: List (or tuple) of x values. Paired by index with ``ys``. Values that
+            are None, bool, NaN or infinite discard that pair. Read defensively.
+        ys: List (or tuple) of y values, parallel to ``xs``. Same defensive rules.
+        x_label: Axis/title label for the x variable. Default "" (falls back to
+            "x" in the title).
+        y_label: Axis/title label for the y variable. Default "" (falls back to
+            "y" in the title).
+        classification: Optional dict from ``classify_relationship_type`` with
+            keys ``tipo, pearson, r2_linear, spearman, r2_poly2, r2_poly3,
+            best_degree, coeffs``. When None, it is computed internally by
+            importing and calling ``classify_relationship_type`` over the clean
+            pairs. When that sibling module is unavailable, the scatter is still
+            drawn (no fit curve, no annotation).
+        max_points: Cap on the number of *plotted* points. When the number of
+            clean pairs exceeds this cap, the drawn cloud is down-sampled by a
+            fixed step ``ceil(n/max_points)`` taking ``pairs[::step]`` —
+            DETERMINISTIC, not random, so the figure is reproducible. A
+            non-positive or non-int value disables down-sampling. Default 2000.
+
+    Returns:
+        A ``matplotlib.figure.Figure`` (figsize 6.4x4.0, dpi 150) with a single
+        scatter Axes, the fitted curve (when a polynomial fit is available) and a
+        corner annotation with the relationship type and metrics. When there are
+        fewer than 2 clean pairs it returns a Figure with a centered "Sin datos
+        suficientes para el scatter" message. The caller rasterizes/closes it.
+    """
+    pairs = _clean_pairs(xs, ys)
+    if len(pairs) < 2:
+        return _no_data_figure("Sin datos suficientes para el scatter")
+
+    # Full clean coordinates feed the classification/fit; the plotted cloud is
+    # what gets thinned.
+    xs_clean = [p[0] for p in pairs]
+    ys_clean = [p[1] for p in pairs]
+
+    # Resolve the classification. If not provided, reuse the sibling classifier
+    # over ALL clean pairs (self-contained). Missing module => no fit/annotation.
+    cls = classification
+    if cls is None:
+        try:
+            from classify_relationship_type import classify_relationship_type
+
+            cls = classify_relationship_type(xs_clean, ys_clean)
+        except Exception:
+            cls = None
+    if not isinstance(cls, dict):
+        cls = {}
+
+    # --- Deterministic down-sampling of the DRAWN points only.
+    n_total = len(pairs)
+    if (
+        isinstance(max_points, int)
+        and not isinstance(max_points, bool)
+        and max_points > 0
+        and n_total > max_points
+    ):
+        step = math.ceil(n_total / max_points)
+        sampled = pairs[::step]
+    else:
+        sampled = pairs
+
+    x_plot = [p[0] for p in sampled]
+    y_plot = [p[1] for p in sampled]
+
+    fig = Figure(figsize=(6.4, 4.0), dpi=150)
+    ax = fig.add_subplot(111)
+
+    ax.scatter(
+        x_plot,
+        y_plot,
+        s=12,
+        alpha=0.5,
+        color=_POINT_COLOR,
+        edgecolors="none",
+        rasterized=True,
+    )
+
+    # --- Fitted curve/line over the full clean x range.
+    coeffs = cls.get("coeffs")
+    best_degree = cls.get("best_degree")
+    tipo = cls.get("tipo")
+    x_min, x_max = min(xs_clean), max(xs_clean)
+    drew_fit = False
+    if coeffs is not None and best_degree is not None and x_max > x_min:
+        try:
+            coeff_arr = np.asarray(coeffs, dtype=float)
+            if coeff_arr.ndim == 1 and coeff_arr.size > 0 and np.all(np.isfinite(coeff_arr)):
+                x_line = np.linspace(x_min, x_max, 200)
+                y_line = np.polyval(coeff_arr, x_line)
+                if np.all(np.isfinite(y_line)):
+                    ax.plot(x_line, y_line, color=_FIT_COLOR, linewidth=2)
+                    drew_fit = True
+        except Exception:
+            # Never fail the figure because of a malformed coeffs array.
+            pass
+
+    # A monotonic non-linear relationship has no fitted polynomial (coeffs is
+    # None by design — a low-degree polynomial would mislead). Draw instead the
+    # ordered trend of y over x so the reader still sees the shape: y averaged
+    # within ordered x-bins (or per distinct x value when x is discrete with few
+    # levels, e.g. an ordinal scale). Defensive: any failure leaves the cloud.
+    if (not drew_fit and isinstance(tipo, str) and "monóton" in tipo.lower()
+            and x_max > x_min):
+        try:
+            xt, yt = _ordered_trend(xs_clean, ys_clean)
+            if xt is not None and len(xt) >= 2:
+                ax.plot(xt, yt, color=_FIT_COLOR, linewidth=2, marker="o",
+                        markersize=3)
+        except Exception:
+            pass
+
+    # --- Labels and title.
+    tx = x_label if x_label else "x"
+    ty = y_label if y_label else "y"
+    ax.set_title(f"{tx} ↔ {ty}", fontsize=12, loc="left", pad=8)
+    ax.set_xlabel(x_label)
+    ax.set_ylabel(y_label)
+
+    # --- Corner annotation: relationship type + available metrics.
+    caption_lines = []
+    if tipo:
+        caption_lines.append(str(tipo))
+    metrics_line = _metrics_caption(cls)
+    if metrics_line:
+        caption_lines.append(metrics_line)
+    if caption_lines:
+        ax.text(
+            0.03,
+            0.97,
+            "\n".join(caption_lines),
+            transform=ax.transAxes,
+            ha="left",
+            va="top",
+            fontsize=8,
+            bbox=dict(
+                boxstyle="round,pad=0.35",
+                facecolor="white",
+                edgecolor="#cccccc",
+                alpha=0.85,
+            ),
+        )
+
+    fig.tight_layout()
+    return fig

python/functions/datascience/relationship_scatter_figure_test.py

@@ -0,0 +1,100 @@
+"""Tests para relationship_scatter_figure (scatter de un par numérico, grupo eda).
+
+Usa el backend Agg sin pyplot global; no muestra ni guarda figuras. Cada test
+cierra explícitamente la Figure construida (matplotlib.pyplot.close) para no
+acumular estado entre tests.
+"""
+
+import os
+import sys
+
+sys.path.insert(0, os.path.dirname(__file__))
+
+import matplotlib
+
+matplotlib.use("Agg")
+
+import matplotlib.pyplot as plt  # noqa: E402
+from matplotlib.collections import PathCollection  # noqa: E402
+from matplotlib.figure import Figure  # noqa: E402
+
+from relationship_scatter_figure import relationship_scatter_figure
+
+
+def _scatter_offsets(fig):
+    """Return the plotted points of the first PathCollection (scatter) found."""
+    for ax in fig.axes:
+        for coll in ax.collections:
+            if isinstance(coll, PathCollection):
+                return coll.get_offsets()
+    return None
+
+
+def test_returns_figure():
+    xs = [float(i) for i in range(20)]
+    ys = [2.0 * x + 1.0 for x in xs]  # y = 2x + 1
+    classification = {
+        "tipo": "lineal",
+        "pearson": 1.0,
+        "r2_linear": 1.0,
+        "spearman": 1.0,
+        "r2_poly2": 1.0,
+        "r2_poly3": 1.0,
+        "best_degree": 1,
+        "coeffs": [2.0, 1.0],
+    }
+    fig = relationship_scatter_figure(
+        xs, ys, x_label="a", y_label="b", classification=classification
+    )
+    assert hasattr(fig, "savefig")
+    assert len(fig.axes) >= 1
+    plt.close(fig)
+
+
+def test_downsample_determinista():
+    n = 5000
+    xs = [float(i) for i in range(n)]
+    ys = [0.5 * x for x in xs]
+    classification = {
+        "tipo": "lineal",
+        "pearson": 1.0,
+        "r2_linear": 1.0,
+        "spearman": 1.0,
+        "r2_poly2": 1.0,
+        "r2_poly3": 1.0,
+        "best_degree": 1,
+        "coeffs": [0.5, 0.0],
+    }
+    fig = relationship_scatter_figure(
+        xs, ys, x_label="x", y_label="y", classification=classification, max_points=1000
+    )
+    assert isinstance(fig, Figure)
+    offsets = _scatter_offsets(fig)
+    assert offsets is not None
+    # El nº de puntos dibujados no debe exceder el cap.
+    assert len(offsets) <= 1000
+    plt.close(fig)
+
+
+def test_empty_no_lanza():
+    fig = relationship_scatter_figure([], [], x_label="x", y_label="y")
+    assert isinstance(fig, Figure)
+    plt.close(fig)
+
+
+def test_classification_none():
+    # Solo se ejecuta si el módulo hermano classify_relationship_type existe.
+    try:
+        import classify_relationship_type  # noqa: F401
+    except Exception:
+        import pytest
+
+        pytest.skip("classify_relationship_type aún no disponible")
+    xs = [float(i) for i in range(30)]
+    ys = [3.0 * x - 2.0 for x in xs]
+    fig = relationship_scatter_figure(
+        xs, ys, x_label="a", y_label="b", classification=None
+    )
+    assert isinstance(fig, Figure)
+    assert len(fig.axes) >= 1
+    plt.close(fig)

python/functions/datascience/summarize_outlier_dims.md

@@ -0,0 +1,79 @@
+---
+name: summarize_outlier_dims
+kind: function
+lang: py
+domain: datascience
+version: "1.0.0"
+purity: pure
+signature: "def summarize_outlier_dims(raw_numeric: dict, outlier_rows: list, top_k: int = 3) -> list"
+description: "Explica QUE columnas hacen rara cada fila anomala detectada por isolation_forest_outliers. Para cada {row_index, score} reconstruye la fila valida (mismo filtro de columnas numericas y mismo descarte de filas con None que el detector, asi row_index coincide) y devuelve las top_k columnas de mayor |z-score| poblacional (ddof=0). Capa de explicabilidad del paso de outliers multivariante en EDA. Pura y determinista; ante entradas vacias/invalidas o sin filas validas devuelve [] sin petar."
+tags: [eda, models, outliers, anomaly-detection, explainability, z-score, multivariate]
+params:
+  - name: raw_numeric
+    desc: "dict {nombre_columna: [valores]} alineado por fila (como ctx['raw_numeric'] del motor AutomaticEDA). Solo se usan columnas con todos los valores numericos (None permitido por fila; bool/str/NaN/Inf descartan la columna entera) — filtro IDENTICO al de isolation_forest_outliers para que row_index coincida."
+  - name: outlier_rows
+    desc: "Lista de {row_index, score} tal cual la devuelve isolation_forest_outliers. row_index cuenta SOLO las filas validas (sin None) en orden de aparicion, base 0. Entradas fuera de rango o malformadas se ignoran defensivamente."
+  - name: top_k
+    desc: "Numero de columnas (las de mayor |z-score|) a reportar por outlier. Default 3. Valores invalidos (no-int, bool, <1) caen a 3."
+output: "Lista paralela a outlier_rows (mismo orden) de dicts {row_index: int, score: float, dims: [{col: str, value: float, z: float}, ...]}. dims trae hasta top_k columnas ordenadas por |z| descendente, con z (z-score poblacional, ddof=0) redondeado a 3 decimales; si una columna tiene std==0 su z es 0. Las entradas de outlier_rows fuera de rango/malformadas se omiten. Ante raw_numeric vacio/no-dict, outlier_rows no-lista, 0 columnas numericas o 0 filas validas devuelve []."
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: ""
+imports: []
+tested: true
+tests: ["test_row_index_skips_none_rows", "test_extreme_row_flagged_via_isolation", "test_out_of_range_row_index_is_ignored", "test_degrades_to_empty_on_invalid_inputs"]
+test_file_path: "python/functions/datascience/summarize_outlier_dims_test.py"
+file_path: "python/functions/datascience/summarize_outlier_dims.py"
+---
+
+## Ejemplo
+
+```python
+from datascience import isolation_forest_outliers, summarize_outlier_dims
+
+# Nube densa alrededor del origen + 1 fila con un valor extremo en "c".
+raw_numeric = {
+    "a": [0.1, 0.2, -0.1, 0.0, 0.3, -0.2, 0.15, -0.05, 0.25, 0.2, -0.3, 0.1],
+    "b": [1.0, 1.1, 0.9, 1.2, 0.8, 1.0, 1.1, 0.95, 1.05, 0.9, 1.15, 1.0],
+    "c": [5.0, 5.2, 4.8, 5.1, 4.9, 5.0, 4.95, 5.05, 4.9, 500.0, 5.1, 5.0],
+}
+
+result = isolation_forest_outliers(raw_numeric, contamination=0.1)
+summary = summarize_outlier_dims(raw_numeric, result["outlier_rows"], top_k=3)
+
+for item in summary:
+    top = item["dims"][0]
+    print(item["row_index"], top["col"], top["value"], top["z"])
+# La fila del valor 500 sale con dim top "c" y |z| alto: es lo que la hace rara.
+```
+
+## Cuando usarla
+
+Justo **despues** de `isolation_forest_outliers`, cuando ya sabes QUE filas son
+anomalas y quieres explicar POR QUE: en que columnas se desvian mas respecto al
+resto. Util para rellenar la seccion de outliers de un report/notebook EDA con
+"la fila 9 es rara sobre todo por `c` (z=+3.3)" en lugar de solo un row_index
+opaco. Pasa el mismo `raw_numeric` que diste al detector y su `outlier_rows`
+intacto; el `row_index` apunta a la misma fila porque ambas funciones aplican el
+mismo filtro de columnas y el mismo descarte de filas con None.
+
+## Gotchas
+
+- **Mismo `raw_numeric` que el detector**: el `row_index` solo coincide si pasas
+  el mismo dict de columnas (mismo orden, mismas listas) con el que llamaste a
+  `isolation_forest_outliers`. Si cambias las columnas o el orden, los indices
+  dejan de mapear.
+- **`row_index` es relativo a las filas validas**: las filas con `None` en
+  cualquier columna usada se descartan y los indices se recalculan sobre las que
+  quedan (base 0, orden de aparicion). No mapea 1:1 con las listas de entrada si
+  hay None.
+- **z-score poblacional (ddof=0)**: se usa la desviacion tipica poblacional,
+  consistente con el escalado del detector. Columnas con `std==0` (todos los
+  valores iguales) dan `z=0`, asi que nunca aparecen como "raras".
+- **Devuelve `[]` en vez de petar**: entrada no-dict/no-lista, 0 columnas
+  numericas, 0 filas validas, o todas las entradas fuera de rango -> lista vacia.
+  No lanza excepciones.
+- **No llama a `isolation_forest_outliers`**: solo consume su salida. Es una
+  funcion independiente (no la importa), por eso `uses_functions` esta vacio.

python/functions/datascience/summarize_outlier_dims.py

@@ -0,0 +1,144 @@
+"""Explica que dimensiones (columnas) hacen rara cada fila anomala.
+
+Toma la salida multivariante de `isolation_forest_outliers` (lista de
+`{row_index, score}`) y, para cada outlier, devuelve las columnas con mayor
+|z-score| respecto a la distribucion de las filas validas. Es la capa de
+"explicabilidad" del paso de outliers multivariante en la fase EDA: el
+Isolation Forest dice QUE filas son raras, esta funcion dice POR QUE (en que
+columnas se desvian mas).
+
+Pura y determinista: reconstruye EXACTAMENTE las mismas "filas validas" que usa
+`isolation_forest_outliers` (mismo filtro de columnas numericas y mismo descarte
+de filas con None), de modo que el `row_index` apunta a la misma fila en ambas
+funciones. No hace I/O ni depende de estado.
+"""
+
+import math
+
+import numpy as np
+
+
+def _is_finite_number(v) -> bool:
+    """True si v es int/float finito. bool NO cuenta; NaN/Inf tampoco."""
+    if isinstance(v, bool):
+        return False
+    if not isinstance(v, (int, float)):
+        return False
+    if isinstance(v, float) and (math.isnan(v) or math.isinf(v)):
+        return False
+    return True
+
+
+def summarize_outlier_dims(
+    raw_numeric: dict,
+    outlier_rows: list,
+    top_k: int = 3,
+) -> list:
+    """Resume las dimensiones que mas desvian a cada fila anomala.
+
+    Args:
+        raw_numeric: dict {nombre_columna: [valores]} alineado por fila (como
+            ctx['raw_numeric'] del motor AutomaticEDA). Solo se usan columnas
+            cuyos valores sean todos numericos (None permitido por fila; bool,
+            str, NaN e Inf descartan la columna entera) — filtro identico al de
+            isolation_forest_outliers.
+        outlier_rows: lista de {row_index, score} tal como la devuelve
+            isolation_forest_outliers. row_index cuenta SOLO las filas validas
+            (sin None) en orden de aparicion, empezando en 0.
+        top_k: numero de columnas (las de mayor |z-score|) a reportar por cada
+            outlier. Default 3. Valores invalidos caen a 3.
+
+    Returns:
+        Lista paralela a outlier_rows (mismo orden) de dicts
+        {row_index, score, dims}, donde dims es la lista de hasta top_k columnas
+        ordenadas por |z| descendente: [{col, value, z}, ...] con z redondeado a
+        3 decimales. Las entradas de outlier_rows fuera de rango o malformadas se
+        omiten (defensivo). Ante raw_numeric vacio/no-dict, outlier_rows
+        no-lista, 0 columnas numericas o 0 filas validas devuelve [].
+    """
+    # Validacion defensiva de los argumentos principales.
+    if not isinstance(raw_numeric, dict) or not isinstance(outlier_rows, list):
+        return []
+    if not isinstance(top_k, int) or isinstance(top_k, bool) or top_k < 1:
+        top_k = 3
+
+    # Seleccion de columnas numericas: identica a isolation_forest_outliers.
+    # Una columna entra solo si todos sus valores son numericos (None permitido
+    # por fila); cualquier bool/str/NaN/Inf descarta la columna completa.
+    numeric_cols: dict[str, list] = {}
+    for name, values in raw_numeric.items():
+        if not isinstance(values, (list, tuple)):
+            continue
+        ok = True
+        for v in values:
+            if v is None:
+                continue
+            if not _is_finite_number(v):
+                ok = False
+                break
+        if ok:
+            numeric_cols[name] = list(values)
+
+    if len(numeric_cols) < 1:
+        return []
+
+    col_names = list(numeric_cols.keys())
+    try:
+        n_rows_total = min(len(numeric_cols[c]) for c in col_names)
+    except ValueError:
+        return []
+
+    # Reconstruye las filas validas con el MISMO criterio que el detector: la
+    # fila i toma un valor por columna; si cualquier valor es None, la fila se
+    # descarta y NO incrementa el indice valido. Asi row_index de outlier_rows
+    # apunta a esta misma secuencia (base 0, orden de aparicion).
+    valid_rows: list[list[float]] = []
+    for i in range(n_rows_total):
+        row = [numeric_cols[c][i] for c in col_names]
+        if any(v is None for v in row):
+            continue
+        valid_rows.append([float(v) for v in row])
+
+    if not valid_rows:
+        return []
+
+    matrix = np.asarray(valid_rows, dtype=float)
+    n_valid = matrix.shape[0]
+    means = matrix.mean(axis=0)
+    stds = matrix.std(axis=0, ddof=0)  # poblacional (ddof=0)
+
+    out: list = []
+    for entry in outlier_rows:
+        if not isinstance(entry, dict):
+            continue
+        ri = entry.get("row_index")
+        # bool es subclase de int: lo excluimos explicitamente.
+        if not isinstance(ri, int) or isinstance(ri, bool):
+            continue
+        if ri < 0 or ri >= n_valid:
+            continue
+
+        try:
+            score = float(entry.get("score"))
+        except (TypeError, ValueError):
+            score = 0.0
+
+        row = matrix[ri]
+        dims = []
+        for j, name in enumerate(col_names):
+            std = stds[j]
+            if std == 0.0:
+                z = 0.0
+            else:
+                z = float((row[j] - means[j]) / std)
+            dims.append({"col": name, "value": float(row[j]), "z": z})
+
+        # Mayor |z| primero; sort estable, empates por orden de columna.
+        dims.sort(key=lambda d: abs(d["z"]), reverse=True)
+        dims = dims[:top_k]
+        for d in dims:
+            d["z"] = round(d["z"], 3)
+
+        out.append({"row_index": int(ri), "score": score, "dims": dims})
+
+    return out

python/functions/datascience/summarize_outlier_dims_test.py

@@ -0,0 +1,93 @@
+"""Tests para summarize_outlier_dims."""
+
+from isolation_forest_outliers import isolation_forest_outliers
+from summarize_outlier_dims import summarize_outlier_dims
+
+
+# Dataset compartido: 3 columnas, 13 filas. La fila ORIGINAL 6 tiene None en "a"
+# (se descarta), de modo que la fila ORIGINAL 10 -- con un valor extremo en "c"
+# -- queda en el indice VALIDO 9 (no 10). Esto verifica el salto de None.
+A = [0.1, 0.2, -0.1, 0.0, 0.3, -0.2, None, 0.15, -0.05, 0.25, 0.2, -0.3, 0.1]
+B = [1.0, 1.1, 0.9, 1.2, 0.8, 1.0, 1.3, 1.1, 0.95, 1.05, 0.9, 1.15, 1.0]
+C = [5.0, 5.2, 4.8, 5.1, 4.9, 5.0, 5.3, 4.95, 5.05, 4.9, 500.0, 5.1, 5.0]
+RAW = {"a": A, "b": B, "c": C}
+
+# Mapa original -> valido (saltando original 6):
+#   orig: 0 1 2 3 4 5 7 8 9 10 11 12
+#  valid: 0 1 2 3 4 5 6 7 8  9 10 11
+# => el extremo en "c" (original 10) esta en el indice valido 9.
+EXTREME_VALID_INDEX = 9
+
+
+def test_row_index_skips_none_rows():
+    # Mapeo directo (sin depender de la aleatoriedad de IsolationForest): el
+    # indice valido 9 debe corresponder a la fila con c == 500 -> el None de la
+    # fila original 6 se salto correctamente.
+    summary = summarize_outlier_dims(
+        RAW, [{"row_index": EXTREME_VALID_INDEX, "score": -0.5}], top_k=3
+    )
+    assert len(summary) == 1
+    entry = summary[0]
+    assert entry["row_index"] == EXTREME_VALID_INDEX
+    assert entry["score"] == -0.5
+    # La dimension dominante es "c", con su valor extremo y |z| alto.
+    top = entry["dims"][0]
+    assert top["col"] == "c"
+    assert top["value"] == 500.0
+    assert abs(top["z"]) > 2.0
+    # top_k respetado: como mucho 3 dims.
+    assert len(entry["dims"]) <= 3
+
+
+def test_extreme_row_flagged_via_isolation():
+    # Integracion real: detectar outliers y explicarlos.
+    result = isolation_forest_outliers(RAW, contamination=0.1)
+    assert "note" not in result
+    outlier_rows = result["outlier_rows"]
+    assert outlier_rows  # al menos un outlier
+
+    summary = summarize_outlier_dims(RAW, outlier_rows, top_k=3)
+    # Paralela a outlier_rows (todos los indices estan en rango).
+    assert len(summary) == len(outlier_rows)
+
+    by_index = {e["row_index"]: e for e in summary}
+    # El punto extremo debe estar entre los outliers detectados...
+    assert EXTREME_VALID_INDEX in by_index
+    # ...y su dimension top debe ser "c" (donde se desvia ~muchas sigmas).
+    extreme = by_index[EXTREME_VALID_INDEX]
+    assert extreme["dims"][0]["col"] == "c"
+    assert abs(extreme["dims"][0]["z"]) > 2.0
+
+
+def test_out_of_range_row_index_is_ignored():
+    # Indices fuera de rango se omiten en lugar de petar.
+    summary = summarize_outlier_dims(
+        RAW,
+        [
+            {"row_index": 999, "score": -1.0},
+            {"row_index": -1, "score": -1.0},
+            {"row_index": EXTREME_VALID_INDEX, "score": -0.5},
+        ],
+        top_k=2,
+    )
+    # Solo sobrevive el indice valido; los otros dos se descartan.
+    assert len(summary) == 1
+    assert summary[0]["row_index"] == EXTREME_VALID_INDEX
+    assert len(summary[0]["dims"]) <= 2
+
+
+def test_degrades_to_empty_on_invalid_inputs():
+    # raw_numeric vacio + outlier_rows vacio.
+    assert summarize_outlier_dims({}, [], 3) == []
+    # raw_numeric no es dict.
+    assert summarize_outlier_dims("not a dict", [{"row_index": 0}], 3) == []
+    # outlier_rows no es lista.
+    assert summarize_outlier_dims(RAW, "not a list", 3) == []
+    # Sin columnas numericas (todas con strings) -> [].
+    assert summarize_outlier_dims(
+        {"s": ["x", "y", "z"]}, [{"row_index": 0, "score": -1.0}], 3
+    ) == []
+    # Entradas malformadas dentro de outlier_rows se ignoran (no petan).
+    assert summarize_outlier_dims(
+        RAW, ["nope", 42, {"no_row_index": 1}], 3
+    ) == []

python/functions/pipelines/render_automatic_eda.py

@@ -261,7 +261,15 @@ def render_automatic_eda(
         md_path = None
         if emit_md:
             md_path = os.path.join(out_dir, base + ".md")
-            rmd = render_automatic_eda_markdown(prof, md_path, meta) or {}
+            # El Markdown es la salida MÁS completa: además del documento por
+            # capítulos (compartido con PDF/PPTX) volca un apéndice con TODOS los
+            # datos numéricos del perfil (matriz de asociación completa, describe
+            # con skew/kurtosis/percentiles, re-expresiones, scores_by_k de
+            # KMeans, estadísticos de normalidad). Se le pasa el `prof` vía
+            # meta['profile']; un meta propio evita alterar el de PDF/PPTX.
+            md_meta = dict(meta)
+            md_meta["profile"] = prof
+            rmd = render_automatic_eda_markdown(prof, md_path, md_meta) or {}
 
         return {
             "status": "ok",