Merged revisions 6906-6907,6909 via svnmerge from

dopplershift · dopplershift · commit 9e9a9e7b3e3d · 2009-02-12T21:24:36.000Z
https://matplotlib.svn.sourceforge.net/svnroot/matplotlib/branches/v0_98_5_maint ........ r6906 | ryanmay | 2009-02-12 14:05:10 -0600 (Thu, 12 Feb 2009) | 1 line Add a demo for getting notified of an Axes' change in view limits. ........ r6907 | ryanmay | 2009-02-12 14:06:50 -0600 (Thu, 12 Feb 2009) | 1 line Remove trailing whitespace. ........ r6909 | ryanmay | 2009-02-12 15:20:09 -0600 (Thu, 12 Feb 2009) | 1 line Make viewlims demo more interesting by using events to regenerate a fractal. ........ svn path=/trunk/matplotlib/; revision=6910
diff --git a/doc/users/event_handling.rst b/doc/users/event_handling.rst
@@ -552,11 +552,4 @@ Exercise solution::
 
     fig.canvas.mpl_connect('pick_event', onpick)
 
-    plt.show()
-
-
-
-
-
-
-
+    plt.show()
diff --git a/examples/event_handling/viewlims.py b/examples/event_handling/viewlims.py
@@ -0,0 +1,79 @@
+# Creates two identical panels.  Zooming in on the right panel will show
+# a rectangle in the first panel, denoting the zoomed region.
+import numpy as np
+import matplotlib.pyplot as plt
+from matplotlib.patches import Rectangle
+
+# We just subclass Rectangle so that it can be called with an Axes
+# instance, causing the rectangle to update its shape to match the
+# bounds of the Axes
+class UpdatingRect(Rectangle):
+    def __call__(self, ax):
+        self.set_bounds(*ax.viewLim.bounds)
+        ax.figure.canvas.draw_idle()
+
+# A class that will regenerate a fractal set as we zoom in, so that you
+# can actually see the increasing detail.  A box in the left panel will show
+# the area to which we are zoomed.
+class MandlebrotDisplay(object):
+    def __init__(self, h=500, w=500, niter=50, radius=2., power=2):
+        self.height = h
+        self.width = w
+        self.niter = niter
+        self.radius = radius
+        self.power = power
+
+    def __call__(self, xstart, xend, ystart, yend):
+        self.x = np.linspace(xstart, xend, self.width)
+        self.y = np.linspace(ystart, yend, self.height).reshape(-1,1)
+        c = self.x + 1.0j * self.y
+        threshold_time = np.zeros((self.height, self.width))
+        z = np.zeros(threshold_time.shape, dtype=np.complex)
+        mask = np.ones(threshold_time.shape, dtype=np.bool)
+        for i in xrange(self.niter):
+            z[mask] = z[mask]**self.power + c[mask]
+            mask = (np.abs(z) < self.radius)
+            threshold_time += mask
+        return threshold_time
+
+    def ax_update(self, ax):
+        ax.set_autoscale_on(False) # Otherwise, infinite loop
+
+        #Get the number of points from the number of pixels in the window
+        dims = ax.axesFrame.get_window_extent().bounds
+        self.width = int(dims[2] + 0.5)
+        self.height = int(dims[2] + 0.5)
+
+        #Get the range for the new area
+        xstart,ystart,xdelta,ydelta = ax.viewLim.bounds
+        xend = xstart + xdelta
+        yend = ystart + ydelta
+
+        # Update the image object with our new data and extent
+        im = ax.images[-1]
+        im.set_data(self.__call__(xstart, xend, ystart, yend))
+        im.set_extent((xstart, xend, ystart, yend))
+        ax.figure.canvas.draw_idle()
+
+md = MandlebrotDisplay()
+Z = md(-2., 0.5, -1.25, 1.25)
+
+fig = plt.figure()
+ax1 = fig.add_subplot(1, 2, 1)
+ax1.imshow(Z, origin='lower', extent=(md.x.min(), md.x.max(), md.y.min(), md.y.max()))
+
+ax2 = fig.add_subplot(1, 2, 2)
+ax2.imshow(Z, origin='lower', extent=(md.x.min(), md.x.max(), md.y.min(), md.y.max()))
+
+rect = UpdatingRect([0, 0], 0, 0, facecolor='None', edgecolor='black')
+rect.set_bounds(*ax2.viewLim.bounds)
+ax1.add_patch(rect)
+
+# Connect for changing the view limits
+ax2.callbacks.connect('xlim_changed', rect)
+ax2.callbacks.connect('ylim_changed', rect)
+
+ax2.callbacks.connect('xlim_changed', md.ax_update)
+ax2.callbacks.connect('ylim_changed', md.ax_update)
+
+plt.show()
