Exporting figure as pdf using savefig() messes up axis background in OS X

[mdboom]

I'm trying to change the axis background on a plot where several imshow() calls render images in various locations via the extent parameter.

When I save a pdf of the figure using savefig(), I lose the background color if the axis displays more than one image. Note that this doesn't happen when exporting a png of the same figure.

Example code and the corresponding output [stackoverflow.com].

Could this be a bug with the MacOSX backend I'm using?

Note: I'm using matplotlib 1.2.1 installed via pip running on Python 2.7.4

[mdboom]

Seems to be unrelated to macosx (which isn't used to produce PDFs). Looking into it now.

[mdboom]

Can you confirm that the attached patch resolves your issue?

[fgb]

Thanks for the clarification on the backend. I'll test this tomorrow and let you know.

[pelson]

This is fine by me, but I wonder why we need to set the RGB to 1? Is there a similar solution here to the one proposed in #1868?

[mdboom]

Yeah -- at the end of the day, it doesn't matter, but maybe it does make sense to be consistent with #1868. I'll fix this up.

[pelson]

👍 LGTM.

[fgb]

👍 This commit resolves my issue. Thanks for the prompt fix!

Note: I can't believe compilation on OS X is so simple these days. I used to patch make.osx before I could do anything, which generally meant looking for the latest links to the dependencies. I guess brew came to the rescue.

[fgb]

Apologies, closed by mistake. I'm assuming you'll close this issue when merging the pull request.

[pelson]

Apologies, closed by mistake. I'm assuming you'll close this issue when merging the pull request.

Yep.

@mdboom - I wonder if it is worth having some alpha in the axis background, just to test that it is working. I also wonder whether we should use some colour in the actual images being drawn, perhaps simply arr = np.arange(12).reshape(3, 4)?

[mdboom]

@pelson: Good suggestions. Done.

[pelson]

Thanks for reporting @fgb - this will be fixed in v1.3.

Nice work @mdboom.

[fgb]

My pleasure. Now I'll be able to include the relevant figures in PDF in my dissertation instead of relying on PNGs. Thanks @mdboom, @pelson!

[pelson]

Now I'll be able to include the relevant figures in PDF in my dissertation instead of relying on PNGs

Cool. Don't forget to cite us: http://matplotlib.org/citing.html 😉

[fgb]

Will not! ✌️