improved testing for colorizer+multinorm

trygvrad · trygvrad · commit f7681c6b6ffb · 2025-09-04T00:09:52.000+02:00
diff --git a/lib/matplotlib/cbook.py b/lib/matplotlib/cbook.py
@@ -691,9 +691,13 @@ def safe_masked_invalid(x, copy=False):
         xm = np.ma.masked_where(~(np.isfinite(x)), x, copy=False)
     except TypeError:
         if len(x.dtype.descr) == 1:
+            # Arrays with dtype 'object' get returned here.
+            # For example the 'c' kwarg of scatter, which supports multiple types.
+            # `plt.scatter([3, 4], [2, 5], c=[(1, 0, 0), 'y'])`
             return x
         else:
-            # in case of a dtype with multiple fields:
+            # In case of a dtype with multiple fields
+            # for example image data using a MultiNorm
             try:
                 mask = np.empty(x.shape, dtype=np.dtype('bool, '*len(x.dtype.descr)))
                 for dd, dm in zip(x.dtype.descr, mask.dtype.descr):
diff --git a/lib/matplotlib/colorizer.py b/lib/matplotlib/colorizer.py
@@ -642,7 +642,7 @@ def _get_colorizer(cmap, norm, colorizer):
 cmap : str or `~matplotlib.colors.Colormap`, default: :rc:`image.cmap`
     The Colormap instance or registered colormap name used to map scalar data
     to colors.""",
-        multi_cmap_doc="""\
+    multi_cmap_doc="""\
 cmap : str, `~matplotlib.colors.Colormap`, `~matplotlib.colors.BivarColormap`\
     or `~matplotlib.colors.MultivarColormap`, default: :rc:`image.cmap`
     The Colormap instance or registered colormap name used to map
@@ -911,9 +911,6 @@ def _ensure_multivariate_data(data, n_components):
                 reconstructed[f][data[i].mask] = np.ma.masked
         return reconstructed
 
-    if data is None:
-        return data
-
     if n_components == 1:
         # PIL.Image gets passed here
         return data
diff --git a/lib/matplotlib/tests/test_colors.py b/lib/matplotlib/tests/test_colors.py
@@ -2195,3 +2195,34 @@ def test_colorizer_multinorm_explicit():
     data = [0.1, 0.2]
     res = (0.100098, 0.375492, 0.650879, 1.)
     assert_array_almost_equal(ca.to_rgba(data), res)
+
+
+def test_colorizer_bivar_cmap():
+    ca = mcolorizer.Colorizer('BiOrangeBlue', [mcolors.Normalize(), 'log'])
+
+    with pytest.raises(ValueError, match='The colormap viridis'):
+        ca.cmap = 'viridis'
+
+    cartist = mcolorizer.ColorizingArtist(ca)
+    cartist.set_array(np.zeros((2, 4, 4)))
+
+    with pytest.raises(ValueError, match='Invalid data entry for multivariate'):
+        cartist.set_array(np.zeros((3, 4, 4)))
+
+    dt = np.dtype([('x', 'f4'), ('', 'object')])
+    with pytest.raises(TypeError, match='converted to a sequence of floats'):
+        cartist.set_array(np.zeros((2, 4, 4), dtype=dt))
+
+    with pytest.raises(ValueError, match='all variates must have same shape'):
+        cartist.set_array((np.zeros(3), np.zeros(4)))
+
+    # ensure masked value is propagated from input
+    a = np.arange(3)
+    cartist.set_array((a, np.ma.masked_where(a > 1, a)))
+    assert cartist.get_array()['f0'].mask[2] is np.False_
+    assert cartist.get_array()['f1'].mask[2] is np.True_
+    assert cartist.get_array()['f1'].mask[1] is np.False_
+
+    # test clearing data
+    cartist.set_array(None)
+    cartist.get_array() is None
diff --git a/lib/matplotlib/tests/test_image.py b/lib/matplotlib/tests/test_image.py
@@ -463,6 +463,7 @@ def test_format_cursor_data_multinorm(data, text):
     from matplotlib.backend_bases import MouseEvent
     fig, ax = plt.subplots()
     cmap_bivar = mpl.bivar_colormaps['BiOrangeBlue']
+    cmap_multivar = mpl.multivar_colormaps['2VarAddA']
 
     # This is a test for ColorizingArtist._format_cursor_data_override()
     # with data with multiple channels.
@@ -483,6 +484,10 @@ def test_format_cursor_data_multinorm(data, text):
     event = MouseEvent('motion_notify_event', fig.canvas, xdisp, ydisp)
     assert im.format_cursor_data(im.get_cursor_data(event)) == text
 
+    im.colorizer._cmap = cmap_multivar
+    event = MouseEvent('motion_notify_event', fig.canvas, xdisp, ydisp)
+    assert im.format_cursor_data(im.get_cursor_data(event)) == text
+
 
 @image_comparison(['image_clip'], style='mpl20')
 def test_image_clip():
