Honour colorbar=False for colour-only corrplot glyphs

CHANGELOG.md

@@ -18,6 +18,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 
 ### Fixed
 
+* `corrplot(..., colorbar=False)` was ignored whenever the glyph method drew
+  colour only (`method="color"` or `"shade"`, or either as an `upper`/`lower`
+  half) — those panels kept their colorbar while every other method honoured the
+  flag. Callers had to reach for `cl_pos="n"` instead. `colorbar=False` now
+  suppresses the colorbar for every method.
 * Documentation: the "New in v0.26" banner linked to the example notebook with a
   path relative to the site root, but the banner renders on every page — from
   anything below the root (`examples/`, `api/`, `getting_started/`) it resolved to

causalts/plotting/corrplot.py

@@ -452,17 +452,13 @@ def corrplot(
             tl_pos = "lt"  # left + top for upper triangle
 
     # --- Default cl_pos ---
-    color_only_methods = {"color", "shade"}
-    active_methods = {method}
-    if upper is not None:
-        active_methods.add(upper)
-    if lower is not None:
-        active_methods.add(lower)
-    has_color_only = bool(active_methods & color_only_methods)
-
+    # ``colorbar=False`` suppresses the colorbar for every glyph method. It used
+    # to be ignored for the colour-only methods ('color', 'shade') on the theory
+    # that they are unreadable without a scale -- but that silently overrode an
+    # explicit argument, so the caller had to reach for ``cl_pos='n'`` instead.
     if cl_pos is None:
         cl_pos = "r"
-    if not colorbar and not has_color_only:
+    if not colorbar:
         cl_pos = "n"
 
     # --- Default grid_color ---

tests/test_plotting.py

@@ -109,3 +109,46 @@ def test_compare_graphs_smoke():
     g2 = g.copy()
     g2[2, 0, 1] = 1
     compare_graphs(g, g2, var_names=["X", "Y", "Z"])
+
+
+def _make_frame():
+    import pandas as pd
+
+    rng = np.random.default_rng(0)
+    return pd.DataFrame(rng.standard_normal((60, 4)), columns=list("ABCD"))
+
+
+def _extra_axes(**kwargs):
+    """Axes added to a fresh figure by one corrplot call (1 = colorbar drawn)."""
+    import matplotlib.pyplot as plt
+
+    from causalts.plotting import corrplot
+
+    fig, ax = plt.subplots()
+    before = len(fig.axes)
+    corrplot(_make_frame(), fig_ax=(fig, ax), **kwargs)
+    added = len(fig.axes) - before
+    plt.close(fig)
+    return added
+
+
+def test_corrplot_smoke():
+    from causalts.plotting import corrplot
+
+    corrplot(_make_frame())
+
+
+def test_corrplot_colorbar_false_suppresses_for_every_method():
+    # Regression: 'color' and 'shade' encode magnitude in the fill alone and
+    # used to draw a colorbar even when the caller passed colorbar=False.
+    for method in ("circle", "square", "ellipse", "number", "color", "shade", "pie"):
+        assert _extra_axes(method=method, colorbar=False) == 0, method
+
+
+def test_corrplot_colorbar_default_still_draws():
+    for method in ("circle", "color", "shade"):
+        assert _extra_axes(method=method) == 1, method
+
+
+def test_corrplot_colorbar_false_with_color_only_half():
+    assert _extra_axes(upper="color", lower="number", colorbar=False) == 0