diff --git a/lib/matplotlib/colors.py b/lib/matplotlib/colors.py
index 5f909d07c190..08fe5c053802 100644
--- a/lib/matplotlib/colors.py
+++ b/lib/matplotlib/colors.py
@@ -1191,17 +1191,13 @@ class ListedColormap(Colormap):
the list will be extended by repetition.
"""
def __init__(self, colors, name='from_list', N=None):
- self.monochrome = False # Are all colors identical? (for contour.py)
if N is None:
self.colors = colors
N = len(colors)
else:
if isinstance(colors, str):
self.colors = [colors] * N
- self.monochrome = True
elif np.iterable(colors):
- if len(colors) == 1:
- self.monochrome = True
self.colors = list(
itertools.islice(itertools.cycle(colors), N))
else:
@@ -1211,7 +1207,6 @@ def __init__(self, colors, name='from_list', N=None):
pass
else:
self.colors = [gray] * N
- self.monochrome = True
super().__init__(name, N)
def _init(self):
@@ -1220,6 +1215,21 @@ def _init(self):
self._isinit = True
self._set_extremes()
+ @property
+ def monochrome(self):
+ """Return whether all colors in the colormap are identical."""
+ # Replacement for the attribute *monochrome*. This ensures a consistent
+ # response independent of the way the ListedColormap was created, which
+ # was not the case for the manually set attribute.
+ #
+ # TODO: It's a separate discussion whether we need this property on
+ # colormaps at all (at least as public API). It's a very special edge
+ # case and we only use it for contours internally.
+ if not self._isinit:
+ self._init()
+
+ return self.N <= 1 or np.all(self._lut[0] == self._lut[1:self.N])
+
def resampled(self, lutsize):
"""Return a new colormap with *lutsize* entries."""
colors = self(np.linspace(0, 1, lutsize))
diff --git a/lib/matplotlib/colors.pyi b/lib/matplotlib/colors.pyi
index 6941e3d5d176..4ecf90164512 100644
--- a/lib/matplotlib/colors.pyi
+++ b/lib/matplotlib/colors.pyi
@@ -130,11 +130,12 @@ class LinearSegmentedColormap(Colormap):
def reversed(self, name: str | None = ...) -> LinearSegmentedColormap: ...
class ListedColormap(Colormap):
- monochrome: bool
colors: ArrayLike | ColorType
def __init__(
self, colors: ArrayLike | ColorType, name: str = ..., N: int | None = ...
) -> None: ...
+ @property
+ def monochrome(self) -> bool: ...
def resampled(self, lutsize: int) -> ListedColormap: ...
def reversed(self, name: str | None = ...) -> ListedColormap: ...
diff --git a/lib/matplotlib/tests/test_colors.py b/lib/matplotlib/tests/test_colors.py
index cc6cb1bb11a7..19c60091e608 100644
--- a/lib/matplotlib/tests/test_colors.py
+++ b/lib/matplotlib/tests/test_colors.py
@@ -74,6 +74,12 @@ def test_resampled():
assert_array_almost_equal(lc(np.nan), lc3(np.nan))
+def test_monochrome():
+ assert mcolors.ListedColormap(["red"]).monochrome
+ assert mcolors.ListedColormap(["red"] * 5).monochrome
+ assert not mcolors.ListedColormap(["red", "green"]).monochrome
+
+
def test_colormaps_get_cmap():
cr = mpl.colormaps
pFad - Phonifier reborn
Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.
Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.
Alternative Proxies:
Alternative Proxy
pFad Proxy
pFad v3 Proxy
pFad v4 Proxy