Add init function to anim decay example

Ensures that the plot is cleared before restarting the animation

Author: jenshnielsen

examples/animation/animate_decay.py

@@ -10,10 +10,16 @@ def data_gen(t=0):
         t += 0.1
         yield t, np.sin(2*np.pi*t) * np.exp(-t/10.)
 
+def init():
+    ax.set_ylim(-1.1, 1.1)
+    ax.set_xlim(0, 10)
+    del xdata[:]
+    del ydata[:]
+    line.set_data(xdata,ydata)
+    return line,
+
 fig, ax = plt.subplots()
 line, = ax.plot([], [], lw=2)
-ax.set_ylim(-1.1, 1.1)
-ax.set_xlim(0, 5)
 ax.grid()
 xdata, ydata = [], []
 
@@ -33,5 +39,5 @@ def run(data):
     return line,
 
 ani = animation.FuncAnimation(fig, run, data_gen, blit=False, interval=10,
-                              repeat=False)
+                              repeat=False, init_func=init)
 plt.show()