This is now fixed in SVN HEAD. Two changes were made:
a) Be more conservative about when segments are simplified based on their length b) Honor the (already existing) path.simplify rcParam in the *Agg backends. John's suggested patch is also a valid workaround, if you don't want to track SVN. path.py lives in /Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/matplotlib on a Mac. Simply replace the line where should_simplify is set to "self.should_simplify = False" Mike Michael Droettboom wrote: > You can hold off on updating. I am actually able to see it now, even on > SVN HEAD. I'll look further and see if I can find a workaround. > > Cheers, > Mike > > Kaushik Ghose wrote: > >> Hi Mike, >> >> I'm using 0.98.3 with the TkAgg backend on Mac OS X. >> >> I will update matplotlib from the site and try again. My attempt to >> use GtkAgg failed presumably because I don't have things set up with >> GTk on my Mac. >> >> best >> -Kaushik >> >> Michael Droettboom wrote: >> >>> I'm not able to reproduce this on matplotlib SVN head with the GtkAgg >>> backend. Which version and backend are you using? >>> >>> Mike >>> >>> Kaushik Ghose wrote: >>> >>>> PS. In the code just disregard the line N = 1000 - it does nothing. >>>> >>>> Ghose, Kaushik wrote: >>>> >>>> >>>>> Hi John, >>>>> >>>>> OK. I've managed to pare it down to the following pattern: >>>>> >>>>> import pylab >>>>> >>>>> N = 1000 >>>>> x = pylab.zeros(200) >>>>> x[1] = .5 >>>>> x[2:24] = 1.0 >>>>> x[24] = .5 >>>>> x[26] = -.5 >>>>> x[27:49] = -1.0 >>>>> x[49] = -.5 >>>>> x = pylab.tile(x, 100) >>>>> pylab.plot(x) >>>>> >>>>> >>>>> The above code is sufficient to repeat the glitch (just resize the >>>>> window to >>>>> check this). The half-way values (0.5) are important - if we have a >>>>> straight >>>>> jump the glitch isn't visible. >>>>> >>>>> I'm sorry but I couldn't find path.py under >>>>> >>>>> /Library/Frameworks/Python.framework/Versions/2.5/lib/python2.5/site-packages/ >>>>> >>>>> >>>>> >>>>> so I couldn't try it out. (Is it under a different place in mac?) >>>>> >>>>> thanks >>>>> -Kaushik >>>>> >>>>> >>>>> >>>>> John Hunter wrote: >>>>> >>>>> >>>>>> On Sat, Dec 27, 2008 at 10:29 AM, Kaushik Ghose >>>>>> <kaushik_gh...@hms.harvard.edu> wrote: >>>>>> >>>>>> >>>>>>> Hi Gang, >>>>>>> >>>>>>> I was plotting some data collected from an ADC and noticed an odd >>>>>>> aliasing >>>>>>> issue. Please see the images on the following site. >>>>>>> >>>>>>> http://assorted-experience.blogspot.com/2008/12/odd-aliasing-issue-with-matplotlib.html >>>>>>> >>>>>>> >>>>>>> >>>>>>> I wonder if there is any way to avoid this kind of aliasing. I >>>>>>> vaguely remember >>>>>>> our old arch-foe (MATLAB) handles this gracefully. I have found >>>>>>> matplotlib's >>>>>>> plotting to be superior to MATLAB's in every way (except for 3D) >>>>>>> and it would be >>>>>>> nice if aliasing could be handled gracefully. >>>>>>> >>>>>>> >>>>>> I'm almost certain this is a result of the path simplification logic. >>>>>> Could you upload some sample data and a self contained script so we >>>>>> can test? >>>>>> You can test this by editing site-packages/path.py and replacing:: >>>>>> >>>>>> self.should_simplify = (len(vertices) >= 128 and >>>>>> (codes is None or np.all(codes <= >>>>>> Path.LINETO))) >>>>>> >>>>>> with:: >>>>>> >>>>>> self.should_simplify = False >>>>>> >>>>>> Michael, perhaps we could override path.should_simplify with an rc or >>>>>> line property? >>>>>> >>>>>> >>>>>> >>>>>>> Also, thanks for the excellent binary packages for Mac! >>>>>>> >>>>>>> >>>>>> Thanks for testing them! >>>>>> >>>>>> >>>>> ------------------------------------------------------------------------------ >>>>> >>>>> >>>>> _______________________________________________ >>>>> Matplotlib-users mailing list >>>>> Matplotlib-users@lists.sourceforge.net >>>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users >>>>> >>>>> >>>> ------------------------------------------------------------------------------ >>>> >>>> >>>> _______________________________________________ >>>> Matplotlib-users mailing list >>>> Matplotlib-users@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users >>>> >>>> >>> -- >>> Michael Droettboom >>> Science Software Branch >>> Operations and Engineering Division >>> Space Telescope Science Institute >>> Operated by AURA for NASA >>> >>> > > -- Michael Droettboom Science Software Branch Operations and Engineering Division Space Telescope Science Institute Operated by AURA for NASA ------------------------------------------------------------------------------ _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
