MatplotlibDeprecationWarning: The global colormaps dictionary is no longer considered public API

[ejeschke]

This deprecation warning appears from this line in ginga.cmap. It looks like matplotlib is trying to deprecate accessing the global colormaps dictionary.

So far I have not found a replacement API for getting the same information using a public API.

[pllim]

Hmm. I haven't seen it. Maybe I am not using a new enough Matplotlib.

[ejeschke]

Seems to be a bleeding-edge version...

[ejeschke]

Looks like we might be able to replace

for name in _cm.cmap_d:

with

for name in _cm._gen_cmap_registry():

But of course that also looks like an internal API, and we'd need to check matplotlib version before trying to access it.

[pllim]

xref matplotlib/matplotlib#16991