add EventCollection demo

toddrjen · toddrjen · commit 5a6eed80f374 · 2013-02-21T19:58:49.000+01:00
diff --git a/examples/pylab_examples/eventcollection_demo.py b/examples/pylab_examples/eventcollection_demo.py
@@ -0,0 +1,54 @@
+#!/usr/bin/env python
+# -*- Coding:utf-8 -*-
+'''Plot two curves, then use EventCollections to mark the locations of the x
+and y data points on the respective axes for each curve'''
+
+import matplotlib.pyplot as plt
+from matplotlib.collections import EventCollection
+import numpy as np
+
+# create random data
+np.random.seed(50)
+xdata = np.random.random([2, 10])
+
+# split the data into two parts
+xdata1 = xdata[0, :]
+xdata2 = xdata[1, :]
+
+# sort the data so it makes clean curves
+xdata1.sort()
+xdata2.sort()
+
+# create some y data points
+ydata1 = xdata1 ** 2
+ydata2 = 1 - xdata2 ** 3
+
+# plot the data
+fig = plt.figure()
+ax = fig.add_subplot(1, 1, 1)
+ax.plot(xdata1, ydata1, 'r', xdata2, ydata2, 'b')
+
+# create the events marking the x data points
+xevents1 = EventCollection(xdata1, color=[1, 0, 0], linelength=0.05)
+xevents2 = EventCollection(xdata2, color=[0, 0, 1], linelength=0.05)
+
+# create the events marking the y data points
+yevents1 = EventCollection(ydata1, color=[1, 0, 0], linelength=0.05,
+                           orientation='vertical')
+yevents2 = EventCollection(ydata2, color=[0, 0, 1], linelength=0.05,
+                           orientation='vertical')
+
+# add the events to the axis
+ax.add_collection(xevents1)
+ax.add_collection(xevents2)
+ax.add_collection(yevents1)
+ax.add_collection(yevents2)
+
+# set the limits
+ax.set_xlim([0, 1])
+ax.set_ylim([0, 1])
+
+ax.set_title('line plot with data points')
+
+# display the plot
+fig.show()
