I'm attaching a copy of my comment to Ben's bug report for a reference. here is a bug report.
https://sourceforge.net/tracker/index.php?func=detail&aid=3010569&group_id=80706&atid=560720# My comment: As far as I can see, this is not a bug of matplotlib, but an artifact of the rasterizer you're using. For example, the pdf file you uploaded looks fine with acrobat reader but shows white lines on gs-based pdf viewer. Even in gs-based viewer, if you turn off anti-aliasing, you will notice that the white lines are gone. I'm not sure if there is anything we can do to avoid this artifact from the matplotlib side. If anyone has any suggestion, please open a new feature request ticket. Meanwhile, I'm closing this ticket. -JJ On Tue, Jun 1, 2010 at 11:21 PM, Benjamin Root <ben.r...@ou.edu> wrote: > I have finally managed to test against TkAgg, and the faint white lines do > not appear to occur. So, as far as I can tell (no clue about Macs), the > GTKCairo, pdf and svg backends have this display bug. Shall I file a bug > report for this and another for the misaligned title? > > Ben Root > > On Tue, Jun 1, 2010 at 1:07 PM, Benjamin Root <ben.r...@ou.edu> wrote: >> >> Correction -- the problem with pcolormesh and the faint white lines are >> occurring for pdf and svg files, *not* eps files as I originally stated. I >> am also checking a number of display backends and found that the problem >> occurs for GTKCairo. I am sure it also happens for TkAgg, but I can not >> confirm that right now. I am unable to test the Mac backends, though. >> >> On a side note, when testing the backends, I noticed that GTKCairo was >> *slow* for displaying the figures. Also, the GTK backend produced >> misaligned titles. I can start a new thread about the misaligned titles, if >> someone wishes. >> >> Ben Root >> >> On Tue, Jun 1, 2010 at 11:05 AM, Benjamin Root <ben.r...@ou.edu> wrote: >>> >>> >>> On Tue, Jun 1, 2010 at 9:39 AM, Ryan May <rma...@gmail.com> wrote: >>>> >>>> On Mon, May 31, 2010 at 11:28 AM, Benjamin Root <ben.r...@ou.edu> wrote: >>>> > Markus, >>>> > >>>> > That is good to know that it has been fixed. As for the difference in >>>> > pcolor and pcolormesh, I think it has to do with the fact that >>>> > pcolormesh is >>>> > composed of many lines while pcolor is composed of many polygons. It >>>> > is >>>> > probably more efficient to rasterize polygons than lines. >>>> >>>> To be blunt, this makes no sense whatsoever. First, pcolormesh and >>>> pcolor differ in that it pcolor uses a generic PolyCollection to draw >>>> the quads, while pcolormesh uses a quadmesh object, which can be more >>>> efficient at the cost of generality, as it only needs to render a set >>>> of identical quads. Second, if you're talking rasterized drawing, in >>>> the end what gets written to a file is a 2D array of RGBA values. It >>>> doesn't matter what you use to produce the results: identical image on >>>> the screen -> identical array in file. It's possible that there are >>>> slight differences that you can't really see that produce different >>>> arrays, but that won't cause a factor of 8 difference in size. My >>>> guess is that pcolormesh isn't rasterizing properly. >>>> >>> Indeed, you are right that lines aren't drawn. I have looked back at the >>> images produced by my test script that I posted to this thread and I see >>> where I got confused. The pcolormesh result in pdf and eps files have very >>> faint white blocks around each quad. At high enough data resolution, the >>> color part of the quads look like lines while the white lines look like >>> dots. This happens regardless of using rasterized=True or not, and I don't >>> think it is visible in png files (although I am testing some very high >>> resolution png files to verify). >>> >>> Ben Root >> > > > ------------------------------------------------------------------------------ > > > _______________________________________________ > Matplotlib-devel mailing list > Matplotlib-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-devel > > ------------------------------------------------------------------------------ ThinkGeek and WIRED's GeekDad team up for the Ultimate GeekDad Father's Day Giveaway. ONE MASSIVE PRIZE to the lucky parental unit. See the prize list and enter to win: http://p.sf.net/sfu/thinkgeek-promo _______________________________________________ Matplotlib-devel mailing list Matplotlib-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
