Re: [Matplotlib-users] Efficient animations w/ 2D plots (imshow)

Nevermind.  I'm an idiot.  I removed the call to update_line() before p.show()
and now it works.  That was cruft left over from earlier experiments
Cheers,
Greg

On 7/24/07, Greg Willden <gre...@gm...> wrote:
>
> Hello All,
> I'm looking for the most efficient way to perform 2D plot animations.
>
> I've been experimenting with the animation examples from the Matplotlib
> cookbook.  More specifically I'm using a version of "Animating selected plot
> elements"  that has been modified to work with wxWidgets.  I want to do the
> same type of thing but with 2D plots ( i.e. imshow).
>
>
> When I try  ax.draw_artist(im) where "im" is the AxesImage returned from
> the initial call to imshow I get an AssertionError for self._cachedRenderer
> is not None.
>
>
> What am I doing wrong?
> Thanks
> Greg
>
>
> Here is my hacked up version of the example.
> <code>
> # The number of blits() to make before exiting
> NBLITS = 1000
>
> import matplotlib
> matplotlib.use('WXAgg')
> matplotlib.rcParams['toolbar'] = None
>
> import wx
> import sys
> import pylab as p
> import matplotlib.numerix as nx
> import time
>
> # allow the user to disable the WXAgg accelerator from the command line
> if '--no-accel' in sys.argv:
>     import matplotlib.backends.backend_wxagg
>     matplotlib.backends.backend_wxagg._use_accelerator(False)
>
> ax = p.subplot(111)
> canvas = ax.figure.canvas
>
> p.subplots_adjust (left=0.3, bottom=0.3) # check for flipy bugs
> p.grid() # to ensure proper background restore
>
> # create the initial line
> appx = 10.0
> appy = 3.8
> delta = 0.125
> x = p.arange(-appx/2.0, appx/2.0, delta)
> y = p.arange(-appy/2.0, appy/2.0, delta)
> X, Y = p.meshgrid(x, y)
> #     bivariate_normal(X, Y,sigmax,sigmay,mux,muy)
> Z = p.bivariate_normal(X, Y, 0.9, 0.7, 4.1, -0.15)
>
> im = p.imshow(Z,cmap=p.cm.hot)
>
> # for profiling
> tstart = time.time()
> blit_time = 0.0
>
> def update_line(*args):
>     global blit_time
>
>     if update_line.background is None:
>         update_line.background = canvas.copy_from_bbox(ax.bbox )
>
>     # restore the clean slate background
>     canvas.restore_region(update_line.background)
>     # update the data
>     im.set_data(p.bivariate_normal(X,Y,
>                                    0.9,0.7,
>                                    4.1+p.sin(update_line.cnt/20.0),
>                                    -0.15+p.cos(update_line.cnt/10.0)))
>     # just draw the animated artist
>     ax.draw_artist(im)
>     # just redraw the axes rectangle
>
>     t = time.time()
>     canvas.blit(ax.bbox)
>     blit_time += time.time() - t
>
>     if update_line.cnt == NBLITS:
>         # print the timing info and quit
>         frame_time = time.time() - tstart
>         print '%d frames: %.2f seconds' % (NBLITS, frame_time)
>         print '%d blits:  %.2f seconds' % (NBLITS, blit_time)
>         print
>         print 'FPS: %.2f' % (NBLITS/frame_time)
>         if blit_time > 0:
>             print 'BPS: %.2f' % (NBLITS/blit_time)
>         global timer
>         timer.Stop()
>
>     update_line.cnt += 1
>
>
>
> update_line.cnt = 0
> update_line.background = None
> TIMER_ID=100
> panel = wx.GetApp()
> global timer
> timer = wx.Timer(panel,TIMER_ID)
> timer.Start(10)
> wx.EVT_TIMER(panel,TIMER_ID, update_line)
> update_line()
> p.show()
>
> </code>
> --
> Linux.  Because rebooting is for adding hardware.




-- 
Linux.  Because rebooting is for adding hardware.