[Matplotlib-users] slowdown when using pcolor and TkAgg; help?

[Russell E. O. <ro...@ce...>]

I have appended some code which draws a varying pcolor plot in a Tkinter 
window. The plot shows two 5x5 white rings which shrink to 3x3 and then 
1x3, then cycles through this repeatedly.

Unfortunately, it slows down with each cycle!!!

Are we doing something wrong? Or can we work around the problem somehow?

(By the way, I did not write the code, though I cleaned up some portions 
of it. I realize the data generation can be cleaned up, but it's not 
slowing things down).

-- Russell

P.S. At risk of distracting from the main problem: I am not entirely 
sure I'm commanding a redraw in the correct fashion. I'm fuzzy on the 
difference between show and plot. Using canvas.show() and canvas.plot() 
both seem to work. Just calling plot() doesn't. Any hints on this or 
pointers to documentation would be appreciated.

Also, is pcolor documented anywhere?

----- the code -----

import Tkinter as Tk
from matplotlib.pylab import *
import matplotlib.numerix as num
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, 
NavigationToolbar2TkAgg

root = Tk.Tk()
a =[ [0,1,2,3,4,5,6,\
90,91,92,93,94,95,96,15,30,45,\
60,75,21,36,51,66,81,\
8,9,10,11,12,13,14,98,99,\
100,101,102,103,104,\
23,38,53,68,83,29,44,59,74,89],\
[16,17,18,19,20,76,77,78,79,80,35,50,65,\
31,46,61,24,25,26,27,28,\
84,85,86,87,88,39,54,69,43,58,73],\
[32,33,34,62,63,64,47,49,40,41,42,\
70,71,72,55,57],\
[48,56] ]

ioff()
f = figure(figsize=(3,3))
sp = f.add_subplot(111)
canvas = FigureCanvasTkAgg(f, master=root)
canvas.get_tk_widget().pack(side=Tk.TOP, fill=Tk.BOTH, expand=1)

def displayData(maxCount=20, delayTimeMS=20, count=0):
    fx = count % len(a)
    a[fx].sort()
    ra = []
    cnt = 0
    v = a[fx][cnt]
    for i in range(15*15):
        if i == v:
            ra.append(1)
            cnt += 1
            if cnt < len(a[fx]):
                v = a[fx][cnt]

        else:
            ra.append(0)

    z = num.reshape(ra, (15,15))
    sp.pcolor(transpose(z), cmap=cm.gray, norm=normalize())
    canvas.draw()
    count += 1
    if count < maxCount:
        root.after(delayTimeMS, displayData, maxCount, delayTimeMS, 
count)

displayData(maxCount=100, delayTimeMS=20)
root.mainloop()