added darrens line collection example

jdh2358 · jdh2358 · commit a21317ef83c5 · 2005-04-28T14:06:11.000Z
svn path=/trunk/matplotlib/; revision=1245
diff --git a/CHANGELOG b/CHANGELOG
@@ -1,5 +1,7 @@
 New entries should be added at the top
 
+2005-04-28 Added Darren's line collection example
+
 2005-04-28 Fixed aa property in agg - JDH
 
 2005-04-27 Set postscript page size in .matplotlibrc - DSD
diff --git a/examples/line_collection.py b/examples/line_collection.py
@@ -0,0 +1,33 @@
+from pylab import *
+from matplotlib.collections import LineCollection
+from matplotlib.colors import ColorConverter
+colorConverter = ColorConverter()
+
+# In order to efficiently plot many lines in a single set of axes,
+# Matplotlib has the ability to add the lines all at once. Here is a
+# simple example showing how it is done.
+
+x = arange(200)
+# Here are many sets of y to plot vs x
+ys = [x+i for i in x]
+
+# We need to set the plot limits, the will not autoscale
+ax = axes()
+ax.set_xlim((amin(x),amax(x)))
+ax.set_ylim((amin(amin(ys)),amax(amax(ys))))
+
+# colors is sequence of rgba tuples
+# linestyle is a string or dash tuple. Legal string values are
+#          solid|dashed|dashdot|dotted.  The dash tuple is (offset, onoffseq)
+#          where onoffseq is an even length tuple of on and off ink in points.
+#          If linestyle is omitted, 'solid' is used
+# See matplotlib.collections.LineCollection for more information
+line_segments = LineCollection([zip(x,y) for y in ys], # Make a sequence of x,y pairs
+                                linewidths    = (0.5,1,1.5,2),
+                                colors        = [colorConverter.to_rgba(i) \
+                                                 for i in ('b','g','r','c','m','y','k')],
+                                linestyle = 'solid')
+ax.add_collection(line_segments)
+show()
+
+
