Index: /trunk/doc/Statistics.doxygen
===================================================================
--- /trunk/doc/Statistics.doxygen (revision 1638)
+++ /trunk/doc/Statistics.doxygen (revision 1639)
@@ -64,4 +64,6 @@
- Setting a weight to zero is equivalent to removing the data point.
+The last point implies that a data point with zero weight is ignored
+also when the value is NaN.
An important case is when weights are binary (either 1 or 0). Then we
get the same result using the weighted version as using the data with