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On Mar 2, 2008, at 3:55 PM, Bryan Cole wrote:
Are you sure you meant that *chaco* is too slow? The stated difference of chaco with matplotlib is interactive plotting and I know a bit of effort goes in to making it fast.
You're quite right to pull me up on this. In fact, I've not tested chaco for this type of application so I can't say for sure if it's fast enough or not. I guess, my expectation was that it would not be much faster than matplotlib (given they both use Antigrain for rendering, which tends to be the bottleneck). Whenever I tried any type of anti-aliased drawing (antigrain or cairo) there is always a significant performance hit (on linux anyway).
Although Chaco uses Agg, the nature of *how* it uses Agg is very different from matplotlib. Also, Chaco's internal architecture is designed around interactivity. There are several examples with displaying live updating data: https://svn.enthought.com/enthought/browser/Chaco/trunk/examples/advanced/da... The spectrum analyzer example at the very bottom of the Chaco gallery uses PyAudio to display a realtime FFT and spectrogram of the sound input: http://code.enthought.com/chaco/gallery/index.shtml Also, Chaco has several different backends it can use for output, not just Agg. I recently greatly improved the OpenGL backend so it is extremely fast on all three major platforms (although this has not been merged into the trunk just yet).
Sounds like I should revisit chaco (I haven't tried it in a while). My main problem with it is lack of documentation (this is really what has prevented me from testing it extensively).
I apologize for the continuing lack of extensive documentation. The examples are a good place to start, and the classes all have some level of comments describing the common traits. I think the data_strea.py example would probably be a good place for you to try out your data acquisition and display. (It does require wxPython.) And, as always, you can email the list with questions. -Peter