[off topic] Re: [Numpy-discussion] numarray speed - PySequence_GetItem
haase at msg.ucsf.edu
Fri Jun 25 15:34:01 CDT 2004
I wanted to try matplotlib a few days ago, but first I had some trouble
compiling it (my debian still uses gcc 2-95, which doesn't understand some
'std' namespace/template stuff) - and then it compiled, but segfaulted.
Maybe I didn't get "set NUMERIX" stuff right - how do I know that it actually
built _and_ uses the wx-backend ?
BTW, from the profiling/timing I did you can tell that wxPyPlot actually plots
25000 data points in 0.1 secs - so it's _really_ fast ...
So it would be nice to get to the ground of this ...
Thanks for the comment,
On Friday 25 June 2004 02:12 pm, John Hunter wrote:
> >>>>> "Sebastian" == Sebastian Haase <haase at msg.ucsf.edu> writes:
> Sebastian> Hi, The long story is that I'm looking for a good/fast
> Sebastian> graph plotting programs; so I found WxPyPlot
> Sebastian> (http://www.cyberus.ca/~g_will/wxPython/wxpyplot.html)
> Sebastian> It uses wxPython and plots 25000 data points (with
> Sebastian> lines + square markers) in under one second - using
> Sebastian> Numeric that is.
> Not an answer to your question ....
> matplotlib has full numarray support (no need to rely on sequence
> API). You need to set NUMERIX='numarray' in setup.py before building
> it *and* set numerix : numarray in the matplotlib rc file. If you
> don't do both of these things, your numarray performance will suffer,
> sometimes dramatically.
> With this test script
> from matplotlib.matlab import *
> N = 25000
> x = rand(N)
> y = rand(N)
> scatter(x,y, marker='s')
> You can do a scatter plot of squares, on my machine in under a second
> using numarray (wxagg or agg backend). Some fairly recent changes to
> matplotlib have moved this drawing into extension code, with an approx
> 10x performance boost from older versions. The latest version on the
> sf site (0.54.2) however, does have these changes.
> To plot markers with lines, you would need
> plot(x,y, marker='-s')
> instead of scatter. This is considerably slower (approx 3s on my
> system), mainly because I haven't ported the new fast drawing of
> marker code to the line class. This is an easy fix, however, and will
> be added in short order.
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