readded the long lost IndexFormatter

jdh2358 · jdh2358 · commit e66091d6a3c4 · 2009-06-12T19:41:58.000Z
svn path=/trunk/matplotlib/; revision=7213
diff --git a/examples/pylab_examples/manual_axis.py b/examples/pylab_examples/manual_axis.py
@@ -1,10 +1,11 @@
 """
-matplotlib is fairly rigid about how and where it draws it xaxis and
-yaxis, and it is a frequent request to be able to place these in other
-locations.  While it is not possible to customize matplotlib's
-internal axis objects in this way, it is not too hard to simply turn
-them off and draw your own axis lines, tick lines, and tick labels
-where and how you want them
+The techniques here are no longer required with the new support for
+spines in matplotlib -- see
+http://matplotlib.sourceforge.net/examples/pylab_examples/spine_placement_demo.html.
+
+This example should be considered deprecated and is left just for demo
+purposes for folks wanting to make a pseudo-axis
+
 """
 
 import numpy as np
diff --git a/lib/matplotlib/ticker.py b/lib/matplotlib/ticker.py
@@ -80,6 +80,9 @@
 :class:`NullFormatter`
     no labels on the ticks
 
+:class:`IndexFormatter`
+    set the strings from a list of labels
+
 :class:`FixedFormatter`
     set the strings manually for the labels
 
@@ -203,6 +206,24 @@ def fix_minus(self, s):
         """
         return s
 
+class IndexFormatter:
+    """
+    format the position x to the nearest i-th label where i=int(x+0.5)
+    """
+    def __init__(self, labels):
+        self.labels = labels
+        self.n = len(labels)
+    def __call__(self, x, pos=None):
+        'Return the format for tick val x at position pos; pos=None indicated unspecified'
+        i = int(x+0.5)
+        if i<0:
+            return ''
+        elif i>=self.n:
+            return ''
+        else:
+            return self.labels[i]
+
+
 class NullFormatter(Formatter):
     'Always return the empty string'
     def __call__(self, x, pos=None):
