added another example

svn path=/trunk/matplotlib/; revision=3393

Author: jdh2358

examples/pick_event_demo3.py

@@ -0,0 +1,82 @@
+import numpy as npy
+from pylab import figure, show
+
+
+X = npy.random.rand(100, 200)
+xs = npy.mean(X, axis=1)
+ys = npy.std(X, axis=1)
+
+fig = figure()
+ax = fig.add_subplot(211)
+ax.set_title('click on point to plot time series')
+line, = ax.plot(xs, ys, 'o', picker=5)  # 5 points tolerance
+ax2 = fig.add_subplot(212)
+
+class PointBrowser:
+    """
+    Click on a point to select and highlight it -- the data that
+    generated the point will be shown in the lower axes.  Use the 'n'
+    and 'p' keys to browse through the next and pervious points
+    """
+    def __init__(self):
+        self.lastind = 0
+
+        self.text = ax.text(0.05, 0.95, 'selected: none',
+                            transform=ax.transAxes, va='top')
+        self.selected,  = ax.plot([xs[0]], [ys[0]], 'o', ms=12, alpha=0.4,
+                                  color='yellow', visible=False)
+        
+    def onpress(self, event):
+        if self.lastind is None: return
+        if event.key not in ('n', 'p'): return
+        if event.key=='n': inc = 1
+        else:  inc = -1
+        
+
+        self.lastind += inc
+        self.lastind = npy.clip(self.lastind, 0, len(xs)-1)
+        self.update()
+        
+    def onpick(self, event):
+
+       if event.artist!=line: return True
+
+       N = len(event.ind)
+       if not N: return True
+
+       # the click locations
+       x = event.mouseevent.xdata
+       y = event.mouseevent.ydata
+
+
+       distances = npy.hypot(x-xs[event.ind], y-ys[event.ind])
+       indmin = distances.argmin()
+       dataind = event.ind[indmin]
+
+       self.lastind = dataind
+       self.update()
+
+    def update(self):
+        if self.lastind is None: return
+
+        dataind = self.lastind
+
+        ax2.cla()
+        ax2.plot(X[dataind])
+
+        ax2.text(0.05, 0.9, 'mu=%1.3f\nsigma=%1.3f'%(xs[dataind], ys[dataind]),
+                 transform=ax2.transAxes, va='top')
+        ax2.set_ylim(-0.5, 1.5)
+        self.selected.set_visible(True)
+        self.selected.set_data(xs[dataind], ys[dataind])
+
+        self.text.set_text('selected: %d'%dataind)
+        fig.canvas.draw()
+
+
+browser = PointBrowser()
+
+fig.canvas.mpl_connect('pick_event', browser.onpick)
+fig.canvas.mpl_connect('key_press_event', browser.onpress)
+
+show()

examples/widgets/span_selector.py

@@ -33,7 +33,7 @@ def onselect(xmin, xmax):
     fig.canvas.draw()
 
 # set useblit True on gtkagg for enhanced performance
-span = SpanSelector(ax, onselect, 'horizontal', useblit=False,
+span = SpanSelector(ax, onselect, 'horizontal', useblit=True,
                     rectprops=dict(alpha=0.5, facecolor='red') )