matplotlib3.3 shading="nearest" compatibility #53
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shading="gouraud" and the (new in matplotlib-3.3) "nearest" shading require the array to be sliced differently, and not flattened.
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That explains so much of the garbage that I had to do to get this to work in the first place. (Looking at the docs:
'flat': ... The dimensions of X and Y should be one greater than those of C; if they are the same as C, then a deprecation warning is raised, and the last row and column of C are dropped.
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My understanding is that if the dimensions of X,Y match C, then it defaults to nearest, but if flat is specified then it will work as before where my _make_pcolormech_slice cuts off the last value).
The question that this leaves me with, is what happens if the shading is specified as flat (or auto), but the dimensions of X,Y is one greater than C as is it supposed to be? This was never something that I considered, but since matplotlib covers it, then I think that we should too.
Please add logic and a test for when flat is specified and the dimensions of X,Y are 1 greater than C. (The logic should be as simple as changing the if statement where my second comment is).
Thank you for this contribution.
animatplot/blocks/image_like.py
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| if self.shading == "auto": | ||
| Nx = self.X.shape[-1] | ||
| Ny = self.Y.shape[0] | ||
| if (Ny, Nx) == self.C.shape[Slice]: |
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If this check fails, such as when the dimensions of X and Y are 1 greater than C, then I think that the logic for handling the flat condition will fail since the _make_pcolormesh_flat_slice method cuts the dimensions of C.
This is the case matplotlib is better set up to handle, and uses X and Y as the positions of the cell corners to be colored according to the value of Z. This case needs to use standard slicing from Block._make_slice() instead of the workaround in Pcolormesh._make_pcolormesh_flat_slice().
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Thanks @t-makaro, you were right. I've fixed the case and added a test. Also added a test for |
I think you might be looking for this PR matplotlib/matplotlib#16258 |
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I just made an 0.4.2 release to get this change out. |
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👍 thanks @t-makaro! |
matplotlib-3.3 adds a new option
shading="nearest"forpcolormesh. This PR makesanimatplotcompatible with that option. Now also works withshading="gouraud"when matplotlib=3.3. Don't know whyshading="gouraud"still doesn't work with matplotlib<=3.2, I guess they changed something in the internals.