Apr 3, 2020 · Apr 3, 2020 · Apr 3, 2020 · Apr 3, 2020 · Apr 3, 2020 · Apr 3, 2020
diff --git a/lib/matplotlib/pyplot.py b/lib/matplotlib/pyplot.py
 import numpy as np

 # We may not need the following imports here:
 from matplotlib.colors import Normalize
 from matplotlib.colors import Normalize, Colormap
 from matplotlib.lines import Line2D
 from matplotlib.text import Text, Annotation
 from matplotlib.patches import Polygon, Rectangle, Circle, Arrow
    matplotlib.cm.register_cmap
    matplotlib.cm.get_cmap
    """
    cmap = cm.get_cmap(cmap)
    cbook._check_isinstance((str, Colormap), cmap=cmap)
    if isinstance(cmap, str):
        name = cmap
        cmap = get_cmap(name)
        rc('image', cmap=name)
    elif isinstance(cmap, Colormap):
        if cmap.name not in cm.cmap_d.keys():
            register_cmap(cmap.name, cmap)
        rc('image', cmap=cmap.name)

    rc('image', cmap=cmap.name)
    im = gci()

    if im is not None:
        im.set_cmap(cmap)
Original file line number	Diff line number	Diff line change
Expand Up		@@ -56,7 +56,7 @@
		import numpy as np

		# We may not need the following imports here:
		from matplotlib.colors import Normalize
		from matplotlib.colors import Normalize, Colormap
		from matplotlib.lines import Line2D
		from matplotlib.text import Text, Annotation
		from matplotlib.patches import Polygon, Rectangle, Circle, Arrow
Expand DownExpand Up		@@ -2069,11 +2069,17 @@ def set_cmap(cmap):
		matplotlib.cm.register_cmap
		matplotlib.cm.get_cmap
		"""
		cmap = cm.get_cmap(cmap)
		cbook._check_isinstance((str, Colormap), cmap=cmap)
		if isinstance(cmap, str):
		name = cmap
		cmap = get_cmap(name)
		rc('image', cmap=name)
		elif isinstance(cmap, Colormap):
		if cmap.name not in cm.cmap_d.keys():
Copy link Contributor greglucasApr 3, 2020 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. You don't need the`.keys()` when checking if something is in a dictionary. tacaswell reacted with thumbs up emoji
		register_cmap(cmap.name, cmap)
		rc('image', cmap=cmap.name)
Copy link Contributor greglucasApr 3, 2020 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. Here you could get into another tricky situation. Say someone hasalready registered a different Colormap under the same name. So, the cmap.name is in the dictionary already, but it is actually pointing to a different colormap and this wouldn't set the global cmap to what you're expecting either. Copy link ContributorAuthor ianhiApr 3, 2020 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. Ah, this is tricky. Perhaps: ifcmap.namenotincm.cmap_d:register_cmap(cmap.name,cmap)elifcmapisnotget_cmap(cmap.name):raisesomesortoferror/warning and in that error/warning explain that they should use`register_cmap` or change the name attribute of their colormap? Also good to note that as originally written this function falls into the same trap. Though I suppose it's not super desirable to maintain backwards compatibility with a silent bug. Copy link Contributor greglucasApr 3, 2020 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. Agreed, something like this would be desirable going forward to make it a little more clear what is going on and raising rather than silently doing something unexpected!

		rc('image', cmap=cmap.name)
		im = gci()

		if im is not None:
		im.set_cmap(cmap)

Expand Down