Therasterization documentation suggests one can addrasterized=True tocontourf, similar topcolormesh. This doesn't do anything besides warn the user thekwarg hasn't been used. Setting the resultingQuadContourSet to rasterised causes another warning, but seems to work fine.#27669 picks up on this.

This PR addresses both issues, still need to add tests.

importmatplotlib.pyplotaspltimportnumpyasnpx=y=np.arange(-3.0,3.01,delta)X,Y=np.meshgrid(x,y)Z=np.exp(-X**2-Y**2)fig,ax=plt.subplots(layout='constrained')CS=ax.contourf(X,Y,Z,10,rasterized=True)# currently causes UserWarning: The following kwargs were not used by contour: 'rasterized'# result isn't rasterized# orCS=plt.contourf(X,Y,Z,10)CS.set_rasterized(True)# currently causes UserWarning: Rasterization of '<matplotlib.contour.QuadContourSet object at 0x10304e3c0>' will be ignored# result is rasterizedfig.savefig('foo.pdf')

(screenshot of) unrasterized foo.pdf

(screenshot of) rasterized foo.pdf

Closes#27669

PR checklist

"closes #0000" is in the body of the PR description tolink the related issue
new and changed code istested
Plotting related features are demonstrated in anexample
New Features andAPI Changes are noted with adirective and release note
Documentation complies withgeneral anddocstring guidelines

AdamOrmondroyd added3 commits

February 5, 2025 18:45

allow rasterization

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use rasterized kwarg

49143a0

add to documentation

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github-actionsbot added the topic: contour label

Feb 5, 2025

AdamOrmondroyd mentioned this pull request

Feb 5, 2025

GrouperView.join() no longer exists, usesharey() insteadhandley-lab/fgivenx#26

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AdamOrmondroyd commentedFeb 9, 2025

I've had a good look and can't see where the test for this would naturally fit in

AdamOrmondroyd marked this pull request as ready for review

February 9, 2025 14:29

rcomer reviewed

Mar 2, 2025

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Thanks@AdamOrmondroyd and sorry you didn't get a response sooner. I thinktest_contour.py would be a reasonable place to add a test.

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rcomer moved this fromNeeds review toWaiting for author inFirst Time Contributors

Mar 3, 2025

AdamOrmondroydand others added4 commits

March 3, 2025 16:38

Fix copied docstring

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Co-authored-by: Ruth Comer <10599679+rcomer@users.noreply.github.com>

Merge branch 'main' into rasterizecontourf

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first pass at test

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Merge branch 'rasterizecontourf' of github.com:adamormondroyd/matplot…

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…lib into rasterizecontourf

AdamOrmondroyd commented

Mar 16, 2025

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tacaswell added this to thev3.11.0 milestone

Mar 17, 2025

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tacaswell commentedMar 17, 2025

I agree on both apologizing that this did not get attention earlier and adding a baseline image.

It is a surprising oversight that this has been missing!

add image comparison

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AdamOrmondroyd commentedMar 17, 2025

Seems to work (screenshot of contour_rasterization.pdf with dpi set to 25dpi)

What tolerance is appropriate forimage_comparison?

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rcomer commentedMar 17, 2025

Usually leaving the tolerance to default is fine. Sometimes it needs to be a little higher to accommodate slightly different results on different platforms. So you can just wait to see if CI passes.