parula colormap mismatch
Closed this issue · 14 comments
ykempf commented
Plotting with parula with Python 3.10 and matplotlib 3.5.1 on Windows 11 throws
Using matplotlib version 3.5.1
Traceback (most recent call last):
File "script.py", line 9, in <module>
pt.plot.plot_colormap3dslice(
File "analysator-master/pyPlots\plot_colormap3dslice.py", line 1065, in plot_colormap3dslice
norm = BoundaryNorm(levels, ncolors=cmapuse.N, clip=True)
File "Python\Python310\lib\site-packages\matplotlib\colors.py", line 1781, in __init__
raise ValueError(f"There are {self._n_regions} color bins "
ValueError: There are 253 color bins including extensions, but ncolors = 64; ncolors must equal or exceed the number of bins
(some paths shortened)
@alhom does not reproduce on his system, so it's unclear what the "actual" cause is.
markusbattarbee commented
Hmm, let's look at this again if someone is able to reproduce on a system we use more often.
ykempf commented
I can reproduce on mahti.
ykempf commented
Sorry.
markusbattarbee commented
Ok. Can you try replacing
analysator/pyPlots/colormaps.py
Line 1118 in 5e6ffa3
cmaps[name] = ListedColormap(data, name=name)with
cmaps[name] = matplotlib.colors.LinearSegmentedColormap.from_list(data, name=name)and see if that helps?
ykempf commented
I modified the import a few lines above but then it throws
Traceback (most recent call last):
File "plot_evol_multiplane.py", line 1, in <module>
import pytools as pt
File "/users/kempf/analysator/pytools.py", line 107, in <module>
import plot
File "/users/kempf/analysator/pyPlots/plot.py", line 40, in <module>
import colormaps as cmaps
File "/users/kempf/analysator/pyPlots/colormaps.py", line 1119, in <module>
cmaps[name] = LinearSegmentedColormap.from_list(data, name=name)
TypeError: from_list() got multiple values for argument 'name'
markusbattarbee commented
ah whoops. Try cmaps[name] = matplotlib.colors.LinearSegmentedColormap.from_list(name, data) instead?
ykempf commented
Traceback (most recent call last):
File "plot_evol_multiplane.py", line 1, in <module>
import pytools as pt
File "/users/kempf/analysator/pytools.py", line 107, in <module>
import plot
File "/users/kempf/analysator/pyPlots/plot.py", line 65, in <module>
plt.register_cmap(name='parula_r', cmap=matplotlib.colors.ListedColormap(cmaps.parula.colors[::-1]))
AttributeError: 'LinearSegmentedColormap' object has no attribute 'colors'
alhom commented
So colors is a member of ListedColormap, not LinearSegmentedColormap (that has the more complex _segmentdata). LinearSegmentedColormap (and the base Colormap class!) has the method reversed that can be used instead to get the reversed cmap, so plt.register_cmap(name='parula_r', cmap=cmaps.parula.reversed)?
ykempf commented
@alhom this yields
Traceback (most recent call last):
File "plot_evol_multiplane.py", line 210, in <module>
plt.savefig(outputdir+outputfile, dpi=300, bbox_inches='tight', pad_inches=0.01)
File "/appl/opt/python/3.8.6-gnu930/lib/python3.8/site-packages/matplotlib-3.3.3-py3.8-linux-x86_64.egg/matplotlib/pyplot.py", line 859, in savefig
res = fig.savefig(*args, **kwargs)
File "/appl/opt/python/3.8.6-gnu930/lib/python3.8/site-packages/matplotlib-3.3.3-py3.8-linux-x86_64.egg/matplotlib/figure.py", line 2311, in savefig
self.canvas.print_figure(fname, **kwargs)
File "/appl/opt/python/3.8.6-gnu930/lib/python3.8/site-packages/matplotlib-3.3.3-py3.8-linux-x86_64.egg/matplotlib/backend_bases.py", line 2193, in print_figure
self.figure.draw(renderer)
File "/appl/opt/python/3.8.6-gnu930/lib/python3.8/site-packages/matplotlib-3.3.3-py3.8-linux-x86_64.egg/matplotlib/artist.py", line 41, in draw_wrapper
return draw(artist, renderer, *args, **kwargs)
File "/appl/opt/python/3.8.6-gnu930/lib/python3.8/site-packages/matplotlib-3.3.3-py3.8-linux-x86_64.egg/matplotlib/figure.py", line 1863, in draw
mimage._draw_list_compositing_images(
File "/appl/opt/python/3.8.6-gnu930/lib/python3.8/site-packages/matplotlib-3.3.3-py3.8-linux-x86_64.egg/matplotlib/image.py", line 131, in _draw_list_compositing_images
a.draw(renderer)
File "/appl/opt/python/3.8.6-gnu930/lib/python3.8/site-packages/matplotlib-3.3.3-py3.8-linux-x86_64.egg/matplotlib/artist.py", line 41, in draw_wrapper
return draw(artist, renderer, *args, **kwargs)
File "/appl/opt/python/3.8.6-gnu930/lib/python3.8/site-packages/matplotlib-3.3.3-py3.8-linux-x86_64.egg/matplotlib/cbook/deprecation.py", line 411, in wrapper
return func(*inner_args, **inner_kwargs)
File "/appl/opt/python/3.8.6-gnu930/lib/python3.8/site-packages/matplotlib-3.3.3-py3.8-linux-x86_64.egg/matplotlib/axes/_base.py", line 2747, in draw
mimage._draw_list_compositing_images(renderer, self, artists)
File "/appl/opt/python/3.8.6-gnu930/lib/python3.8/site-packages/matplotlib-3.3.3-py3.8-linux-x86_64.egg/matplotlib/image.py", line 131, in _draw_list_compositing_images
a.draw(renderer)
File "/appl/opt/python/3.8.6-gnu930/lib/python3.8/site-packages/matplotlib-3.3.3-py3.8-linux-x86_64.egg/matplotlib/artist.py", line 41, in draw_wrapper
return draw(artist, renderer, *args, **kwargs)
File "/appl/opt/python/3.8.6-gnu930/lib/python3.8/site-packages/matplotlib-3.3.3-py3.8-linux-x86_64.egg/matplotlib/collections.py", line 2024, in draw
self.update_scalarmappable()
File "/appl/opt/python/3.8.6-gnu930/lib/python3.8/site-packages/matplotlib-3.3.3-py3.8-linux-x86_64.egg/matplotlib/collections.py", line 855, in update_scalarmappable
self._facecolors = self.to_rgba(self._A, self._alpha)
File "/appl/opt/python/3.8.6-gnu930/lib/python3.8/site-packages/matplotlib-3.3.3-py3.8-linux-x86_64.egg/matplotlib/cm.py", line 333, in to_rgba
rgba = self.cmap(x, alpha=alpha, bytes=bytes)
File "/appl/opt/python/3.8.6-gnu930/lib/python3.8/site-packages/matplotlib-3.3.3-py3.8-linux-x86_64.egg/matplotlib/colors.py", line 568, in __call__
self._init()
File "/appl/opt/python/3.8.6-gnu930/lib/python3.8/site-packages/matplotlib-3.3.3-py3.8-linux-x86_64.egg/matplotlib/colors.py", line 760, in _init
self.N, self._segmentdata['red'], self._gamma)
TypeError: 'NoneType' object is not subscriptable
markusbattarbee commented
parula_r can be constructed in colormaps.py the same way e.g. hot_desaturated_colormap_r is, and then registered in plot.py
ykempf commented
So the reversed() works, but do you prefer the other way?
alhom commented
LinearSegmentedColormap.reversed() was added six years ago to Matplotlib. Is that good enough backwards compatibility? v.2.1.
alhom commented
Is this issue still an issue?