I believe I have a fix in r8691 (both branch and trunk). Cheers, Mike
On 09/03/2010 03:31 PM, Eric Firing wrote: > On 09/03/2010 09:14 AM, Tony S Yu wrote: > >> On Sep 3, 2010, at 10:23 AM, Sébastien Barthélemy wrote: >> >> >>> CC to matplotlib-devel& matplotlib-users >>> >>> 2010/9/3 Tony S Yu<tsy...@gmail.com>: >>> >>>> On Sep 3, 2010, at 4:33 AM, Sébastien Barthélemy wrote: >>>> >>>> >>>>> Hello, >>>>> >>>>> While using sage [1], I got problems drawing a line: for some reason, >>>>> the points with negative coordinates are not plotted (or are plotted >>>>> on top of others due to an offset problem and thus I cannot see them). >>>>> I can only reproduce the bug with specific data sets. >>>>> >>>>> [1] www.sagemath.org >>>>> >>>>> I think I could track down the bug to matplotlib, which sage uses to >>>>> render 2d plots. >>>>> >>>>> I included a sage script which generates the data set (in a pickle >>>>> file), and a python script which draws the faulty line. >>>>> >>>>> Usage is : >>>>> >>>>> $ sage generate_data.sage >>>>> $ python test_mpl.py >>>>> >>>>> I also included the pickled data, thus you don't need sage at all. >>>>> I use matplotlib 1.0.0 for python 2.6 on mac os (as provided by macport). >>>>> >>>>> Could somebody here confirm the problem, and give me a hint about what >>>>> is going on? >>>>> >>>> I can confirm the issue. >>>> >>> Great, thank you. I filed a bug: >>> https://sourceforge.net/tracker/?func=detail&aid=3058804&group_id=80706&atid=560720 >>> >>> >>>> This appears to be a drawing bug: when I pan the drawing so that the >>>> negative data touches the edge of the axes frame, the rest of the line is >>>> drawn. So the line object is being created, but for some reason it's not >>>> being drawn correctly. >>>> >>>> The bug is really finicky: if I plot starting from the 3rd value of your >>>> data (i.e. slice xdata, ydata with [2:]), the line is drawn completely. >>>> The strange thing is that the first 100 or so data points defines the >>>> exact same point, so there's noting special about those first two points. >>>> (but this overlaying of data may be related to the bug) >>>> >>>> I've reproduced the issue on TkAgg, Qt4Agg, and MacOSX backends, so maybe >>>> the bug is in backend_bases. (Note: unlike Agg backends, MacOSX backend >>>> doesn't show line even after panning the plot) >>>> >>>> I don't really know how to debug drawing errors like this; so this is as >>>> far as can get. >>>> >> I'm not sure if I should respond to this email or the bug report, but since >> I made the claim here, I'll correct myself here: The bug is not in the >> drawing code as I had suggested. >> >> The bug is related to path simplification. If you turn off path >> simplification (e.g. plt.rc('path', simplify=False), the line is drawn in >> its entirety. This also explains why the bug disappeared when I trimmed the >> first two points: path simplification is triggered from data sets with >> atleast 128 points (your data has 129, so trimming two points turned off >> path simplification). >> >> I just wanted to correct my earlier comments. >> >> > Tony, > > Thanks--it's in a comment added to the bug report. Also, this is the > same problem as reported earlier by Jens Nie. The bug is in > path_converters.h. I think I found part of it, but a real solution may > require more than a changed line or two, and I can't spend more time on > it at the moment. Mike D. could figure it out quickly, but I think he > is not available right now. > > Eric > > >> -T >> >> >> >> ------------------------------------------------------------------------------ >> This SF.net Dev2Dev email is sponsored by: >> >> Show off your parallel programming skills. >> Enter the Intel(R) Threading Challenge 2010. >> http://p.sf.net/sfu/intel-thread-sfd >> _______________________________________________ >> Matplotlib-devel mailing list >> Matplotlib-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel >> > > > ------------------------------------------------------------------------------ > This SF.net Dev2Dev email is sponsored by: > > Show off your parallel programming skills. > Enter the Intel(R) Threading Challenge 2010. > http://p.sf.net/sfu/intel-thread-sfd > _______________________________________________ > Matplotlib-devel mailing list > Matplotlib-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-devel > -- Michael Droettboom Science Software Branch Space Telescope Science Institute Baltimore, Maryland, USA ------------------------------------------------------------------------------ This SF.net Dev2Dev email is sponsored by: Show off your parallel programming skills. Enter the Intel(R) Threading Challenge 2010. http://p.sf.net/sfu/intel-thread-sfd _______________________________________________ Matplotlib-devel mailing list Matplotlib-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
