Plots with many subplots can be slow

[mdboom]

Originally reported by John Gu on the mailing list thread "extreme navigation slowness for subplots".
#549 was a proposed solution to the problem that did not seem to create improvement for all users.

Script to reproduce the issue:

x = arange(1000)
y = x

f = figure(1)
for ia in xrange(5):
     for ib in xrange(5):
         ax = subplot(5,5,ia*5+ib+1, navigate=True)
         ax.plot(x,y)

[efiring]

The lack of improvement that I reported with #549 has always bothered me; it was an impression, not a measurement. So, I went back to it, and tried timing plt.draw() with the array of subplots. I find there is an improvement on my machine, from 0.53 s per draw to 0.37 s per draw; it just wasn't dramatic enough to be visually obvious when I was testing by manual zooming and panning. Maybe it is still worthwhile, if on a substantial sample of machines the improvement is more tangible. The extra complexity does make me hesitate, though.

[mdboom]

I tend to agree -- anytime caching is introduced to speed something up, things can get much more brittle to change and full of unintended side effects. #549 does somewhat illustrate where a good 40% of the time is going though -- there just might be a better way to speed it up than just caching.

[tacaswell]

Closing this as no work has been done on it in 2 years and the assumption that Moore's Law is on our side.

[cvanelteren]

Is there any update on this? I currently need to have a figure containing 16 x 33 subplots and it takes ages to load.

[efiring]

It sounds like the relevant issue is #6664, in particular #6664 (comment).