Re: [Matplotlib-users] Couldn't save animation as gif

[Christoph G. <cg...@uc...>]

On 10/13/2013 7:49 PM, Aiyong WANG wrote:
> Today I setuped a ubuntu virtual machine, installed matplotlib 1.3.1
> (builded and installed from source), installed ImageMagick via
> 'apt-get', and tried again that sample.
> It worked.
>
> So Does the imagemagick writer not work on Windows, or am I missing
> something in my Win7 ?
>
> Can anybody help ?
> Thank you.
>
>
> 2013/10/13 Aiyong WANG <gep...@gm... <mailto:gep...@gm...>>
>
>     Hi.
>     I'm using windows 7, with python(x,y) 2.7.5.0 installed. I then
>     installed matplotlib 1.3.1 and imagemagick.
>     Something goes wrong when try to save animation as a gif file.
>     I used a base_animation.py within ipython notebook as followed:
>
>     code:
>     -------------------------------------------------------------------------------------
>     import numpy as np
>     from matplotlib import pyplot as plt
>     from matplotlib import animation
>     # First set up the figure, the axis, and the plot element we want to
>     animate
>     fig = plt.figure()
>     ax = fig.add_subplot(111, xlim=(0, 2), ylim=(-2, 2))
>     line, = ax.plot([], [], lw=2)
>     # initialization function: plot the background of each frame
>     def init():
>          line.set_data([], [])
>          return line,
>     # animation function.  This is called sequentially
>     def animate(i):
>          x = np.linspace(0, 2, 1000)
>          y = np.sin(2 * np.pi * (x - 0.01 * i))
>          line.set_data(x, y)
>          return line,
>     # call the animator.  blit=True means only re-draw the parts that
>     have changed.
>     anim = animation.FuncAnimation(fig, animate, init_func=init,
>                                     frames=100, interval=20, blit=True)
>     # this is how you save your animation to file:
>     #anim.save('animation.gif', writer='imagemagick_file', fps=30)
>     anim.save('animation.gif', writer='imagemagick', fps=30)
>     plt.show()
>     ----------------------------------------------------------------------------------
>
>
>
>     And I got an error message like this:
>
>     ---------------------------------------------------------------------------
>     RuntimeError                               Traceback (most recent call last)
>     <ipython-input-2-7b2f7b9edcb4>  in<module>()
>           26  # this is how you save your animation to file:
>           27  #anim.save('animation.gif', writer='imagemagick_file', fps=30)
>     ---> 28  anim.save('animation.gif',  writer='imagemagick',  fps=30)
>           29
>           30  plt.show()
>
>     D:\Python27\lib\site-packages\matplotlib\animation.pyc  insave(self, filename, writer, fps, dpi, codec, bitrate, extra_args, metadata, extra_anim, savefig_kwargs)
>          716                      #TODO: Need to see if turning off blit is really necessary
>          717                      anim._draw_next_frame(d,  blit=False)
>     --> 718                  writer.grab_frame(**savefig_kwargs)
>          719
>          720          # Reconnect signal for first draw if necessary
>
>     D:\Python27\lib\site-packages\matplotlib\animation.pyc  ingrab_frame(self, **savefig_kwargs)
>          202              # frame format and dpi.
>          203              self.fig.savefig(self._frame_sink(), format=self.frame_format,
>     --> 204                               dpi=self.dpi, **savefig_kwargs)
>          205          except  RuntimeError:
>          206              out,  err=  self._proc.communicate()
>
>     D:\Python27\lib\site-packages\matplotlib\figure.pyc  insavefig(self, *args, **kwargs)
>         1419              self.set_frameon(frameon)
>         1420
>     -> 1421          self.canvas.print_figure(*args,  **kwargs)
>         1422
>         1423          if  frameon:
>
>     D:\Python27\lib\site-packages\matplotlib\backend_bases.pyc  inprint_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, **kwargs)
>         2218                  orientation=orientation,
>         2219                  bbox_inches_restore=_bbox_inches_restore,
>     -> 2220                  **kwargs)
>         2221          finally:
>         2222              if  bbox_inchesand  restore_bbox:
>
>     D:\Python27\lib\site-packages\matplotlib\backends\backend_agg.pyc  inprint_raw(self, filename_or_obj, *args, **kwargs)
>          495              close=  False
>          496          try:
>     --> 497              renderer._renderer.write_rgba(filename_or_obj)
>          498          finally:
>          499              if  close:
>
>     RuntimeError: Error writing to file
>
>     --
>
>     Can anybody help?
>     ------------------------------------------------------------------
>     WANG Aiyong
>
>
>
>
> --
> ------------------------------------------------------------------
> WANG Aiyong


`convert.exe` is a Windows system file. Set `animation.convert_path` in 
`matplotlib.rc` to the full path to ImageMagick's `convert.exe`. Works 
for me.

Christoph