Getting blitting to work in funcAnimation embedded in PyQT4 GUI

Question

Starting with the working Matplotlib animation code shown below, my goal is to embed this animation (which is just a circle moving across the screen) within a PyQT4 GUI.

Answer 1

After looking at the source code of the animation module, I realized that there is an error in the Animation class (the dictionary bg_cache is empty, when it is accessed for the first time with blitting switched on).

This is fixed in the git version of matplotlib; however, in the most recent stable version 1.5.1, the bug is still present. You can either fix the bug in the matplotlib code itself or you can make a subclass to FuncAnimation. I chose that way, because it should still work after updating matplotlib.

from matplotlib import animation

class MyFuncAnimation(animation.FuncAnimation):
    """
    Unfortunately, it seems that the _blit_clear method of the Animation
    class contains an error in several matplotlib verions
    That's why, I fork it here and insert the latest git version of
    the function.
    """
    def _blit_clear(self, artists, bg_cache):
        # Get a list of the axes that need clearing from the artists that
        # have been drawn. Grab the appropriate saved background from the
        # cache and restore.
        axes = set(a.axes for a in artists)
        for a in axes:
            if a in bg_cache: # this is the previously missing line
                a.figure.canvas.restore_region(bg_cache[a])

Then, simpy use MyFuncAnimation instead of animation.FuncAnimation.

Took me a while to figure it out, but I hope it helps anybody.