added simple gtk animation example

svn path=/trunk/matplotlib/; revision=5857

Author: jdh2358

examples/animation/simple_anim_gtk.py

@@ -0,0 +1,30 @@
+"""
+A simple example of an animated plot using a gtk backends
+"""
+import time
+import numpy as np
+import matplotlib
+matplotlib.use('GTKAgg') # do this before importing pylab
+
+import matplotlib.pyplot as plt
+
+fig = plt.figure()
+
+ax = fig.add_subplot(111)
+
+def animate():
+    tstart = time.time()                 # for profiling
+    x = np.arange(0, 2*np.pi, 0.01)        # x-array
+    line, = ax.plot(x, np.sin(x))
+
+    for i in np.arange(1,200):
+        line.set_ydata(np.sin(x+i/10.0))  # update the data
+        fig.canvas.draw()                         # redraw the canvas
+    print 'FPS:' , 200/(time.time()-tstart)
+    raise SystemExit
+
+import gobject
+print 'adding idle'
+gobject.idle_add(animate)
+print 'showing'
+plt.show()