--- a/dataset.py	Tue Mar 25 11:39:02 2008 -0400
+++ b/dataset.py	Tue Mar 25 13:38:51 2008 -0400
@@ -191,6 +191,15 @@
         return ArrayDataSet(data=self.data[apply(slice,slice_args)],fields=self.fields)
 
     def __array__(self):
+        """Return an view of this dataset which is an numpy.ndarray
+
+        Numpy uses this special function name to retrieve an ndarray view for
+        function such as numpy.sum, numpy.dot, numpy.asarray, etc.
+
+        If this dataset has no fields, then we simply return self.data,
+        otherwise things are complicated. 
+        - why do we want this behaviour when there are fields? (JB)
+        """
         if not self.fields:
             return self.data
         # else, select subsets of columns mapped by the fields