[PD] variance from mapping library

[Oded Ben-Tal]

I'm not sure if it's a bug but:
when using variance (from mapping library) - I get negative numbers. Since 
variance is supposed to be always positive and I don't see anything wrong in the way 
the abstraction is done, I presume there is something I'm missing.
My impression is that small changes in the input translate to negative 
'variance'



___________________________________________________
Oded Ben-Tal
http://ccrma.stanford.edu/~oded
oded at ccrma.stanford.edu