slowdown when using pcolor and TkAgg; help?

Thanks. That was helpful -- though also a bit confusing,

    > in that I'm using the TkAgg back end and calling
    > pylab.draw() doesn't update anything visible on my
    > FigureCanvasAgg object. (As an aside, calling show() on
    > my FigureCanvasAgg object seems to work -- the code
    > originally did that when I got it -- but the manual and
    > FAQ clearly point to using draw instead).

I looked back over the code you posted previously and see that you are
using the API, eg making your own tk canvases. In this case you
should not import pylab at all. Do everything from the class API.
Call canvas.draw() rather than pylab.draw().

You can still use matplotlib.numerix to get all the Numeric/numarray
symbols, but the pylab interface doesn't mix well with the API
interface because pylab tries to manage figure creation and
destruction for you.

Instead of

  f = figure(figsize=(3,3)) # this is a pylab call
  sp = f.add_subplot(111)
  canvas = FigureCanvasTkAgg(f, master=root)


from matplotlib.figure import Figure

  f = Figure(figsize=(3,3)) # this is an API call
  sp = f.add_subplot(111)
  canvas = FigureCanvasTkAgg(f, master=root)

See also examples/ and this post for a tutorial introduction
the matplotlib API

Hope this helps,