Re: [Matplotlib-users] dynamic update in TkAgg ? (more)

[John H. <jdh...@ac...>]

>>>>> "Todd" == Todd Miller <jm...@st...> writes:

    Todd> I tried porting anim.py to TkAgg this morning and got it
    Todd> basically working.  There are two things that might account
    Todd> for the trouble you've been having:

    Todd> 1.  With TkAgg, at least for now, you have to call the
    Todd> figure manager show() method with each cycle rather than the
    Todd> canvas draw() method.

Would it be possible to reorganize tkagg so that a call to canvas.draw
also triggers a blit so that the interface could be more consistent
across backends?

    Todd> 2.  The Tk timed event system requires re-registering the
    Todd> handler with each cycle.

Or you can do something like this

  def updatefig(*args):
      updatefig.count += 1
      lines[0].set_ydata(X[:,updatefig.count%60])
      manager.show()
      return updatefig.count
  updatefig.count=-1

  while 1:
      cnt = updatefig()
      if cnt==100: break
    
    Todd> Performance was better than I thought it would be but still
    Todd> kinda slow.

I profiled this because it was slower than I expected.  Turns out that
there is a huge performance hit in the changes I made to Text to
handle arbitrary rotations (a lot of time spent in Matrix getitem,
multiply, etc...).  With text I could get only 5 frames per second;
w/o text I get 13 fps.  The good news is that it will be easy to
optimize away most of the text based performance hit using more
efficient matrix operations and caching.

This can likely be improved further by using collections for drawing
markers in the line class.

Gary: did Todd's example help you enough to speed you on your way?

JDH