I just did a quick benchmark, and this PR reduces the runtime of the following script from 16s to 10s on my old MBP (speedup might be higher on systems with more cores):

importnumpyasnpimportmatplotlib.pyplotaspltfig=plt.figure()ax=fig.gca(projection='3d')x=y=np.linspace(-1,1,400)x,y=np.meshgrid(x,y)z=x**2+y**2ax.plot_surface(x,y,z,rstride=1,cstride=1)fig.savefig('dump.png')plt.close()

Also note that I haven't added any tests because I've checked that existingplot_surface tests trigger both code paths.

@anntzer I added the padding in#16699.

let's keep that discussion in the corresponding PR then.

@anntzer Please see if the_array_patch_perimeters comment is satisfactory now. I think all your concerns should be addressed now.

looks great, just needs a second positive review.
you may also consider squashing your commits.

Is there any reason to prefer squashing on my side to merge + squash on GitHub? I've usually done the latter for most projects. What's the policy here?

I think it's mostly habit, though perhaps@tacaswell will have an opinion there :)

Personally, I dislike GitHub squash merge because it breaks contributors'git prune +git branch -d.

Small correction, parameter names in docstrings should be*var*, not**var**.

@QuLogic I've applied the suggested changes and added an example for_unfold.

Thanks, the example is quite helpful.

Do you want to squash this?

@QuLogic done!

Failure looks like disk / filesystem related problems.

Thanks@apaszke ! Congratulations on your first Matplotlib PR 🎉 hopefully we will hear from you again.

Failure was#16735.

@tacaswell Thanks! I already havea few followup PRs posted, so I'd appreciate reviews on those!

Also thanks to reviewers for helping to get this in!