On 12/09/2007, Robert Kern <[EMAIL PROTECTED]> wrote:

> That sentence applies to the 3-argument form, which has nothing to do with
> nonzero() and does not yield a tuple. But in general, yes, the docstring 
> leaves
> much to be desired.

Well, here's what I hope is a step in the right direction.

Anne
Index: numpy/add_newdocs.py
===================================================================
--- numpy/add_newdocs.py	(revision 4028)
+++ numpy/add_newdocs.py	(working copy)
@@ -339,19 +339,28 @@
     """)
 
 add_newdoc('numpy.core.multiarray','where',
-    """where(condition, | x, y)
+    """where(condition) or where(condition, x, y)
 
-    The result is shaped like condition and has elements of x and y where
-    condition is respectively true or false.  If x or y are not given,
-    condition.nonzero() is returned.
+    For the three-argument form, the result is shaped like condition and 
+    has elements of x and y where condition is respectively true or false.  
+    For example, to take the absolute value of a:
 
+        where(a>=0, a, -a)
+    
+    
+    If x and y are not given, condition.nonzero() is returned. This has 
+    the effect of returning a tuple suitable for fancy indexing.
     To group the indices by element, rather than dimension, use
 
         transpose(where(condition))
 
     instead. This always results in a 2d array, with a row of indices for
-    each element that satisfies the condition.
+    each element that satisfies the condition, so that 
 
+        transpose(where(a<0))[i]
+
+    is a vector you can use to select the ith negative entry of a.
+
     """)
 
 
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