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

[Aiyong W. <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 in save(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 in
grab_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 in savefig(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 in
print_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_inches and restore_bbox:
D:\Python27\lib\site-packages\matplotlib\backends\backend_agg.pyc in
print_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