added cohere demo

jdh2358 · jdh2358 · commit 6f14e13e63e3 · 2007-10-29T19:00:25.000Z
svn path=/trunk/matplotlib/; revision=4062
diff --git a/examples/backend_driver.py b/examples/backend_driver.py
@@ -32,9 +32,10 @@
     'barh_demo.py',
     'color_demo.py',
     'colorbar_only.py',
+    'cohere_demo.py',
     'contour_demo.py',
     'contourf_demo.py',
-    'csd_demo.py',
+    'csd_demo.py',    
     'custom_ticker1.py',
     'customize_rc.py',
     'date_demo1.py',
diff --git a/examples/cohere_demo.py b/examples/cohere_demo.py
@@ -0,0 +1,37 @@
+#!/usr/bin/env python
+"""
+Compute the coherence of two signals
+"""
+import numpy as n
+
+from pylab import figure, show
+
+dt = 0.01
+t = n.arange(0, 30, dt)
+Nt = len(t)
+nse1 = n.random.randn(Nt)                 # white noise 1
+nse2 = n.random.randn(Nt)                 # white noise 2
+r = n.exp(-t/0.05)
+
+cnse1 = n.convolve(nse1, r)*dt   # colored noise 1
+cnse1 = cnse1[:Nt]
+cnse2 = n.convolve(nse2, r)*dt   # colored noise 2
+cnse2 = cnse2[:Nt]
+
+# two signals with a coherent part and a random part
+s1 = 0.01*n.sin(2*n.pi*10*t) + cnse1
+s2 = 0.01*n.sin(2*n.pi*10*t) + cnse2
+
+fig = figure()
+ax = fig.add_subplot(211)
+ax.plot(t, s1, 'b-', t, s2, 'g-')
+ax.set_xlim(0,5)
+ax.set_xlabel('time')
+ax.set_ylabel('s1 and s2')
+
+ax = fig.add_subplot(212)
+cxy, f = ax.cohere(s1, s2, 256, 1./dt)
+
+show()
+
+
diff --git a/examples/image_slices_viewer.py b/examples/image_slices_viewer.py
@@ -17,7 +17,7 @@ def __init__(self, ax, X):
         self.update()
 
     def onscroll(self, event):
-
+        print event.button
         if event.button=='up':
             self.ind = numpy.clip(self.ind+1, 0, self.slices-1)
         else:
