David Mertz, Ph.D. writes:

 > > I have a distribution for you: Cauchy.  :-)
 > >
 >
 > Oh? Because NaN is the *result* of `stats.variance(cauchy)`?
 >
 > It still seems like as INPUTS to a stats function NaN ~= missing.

Well, that was a little opaque.  I wanted to fit it into the "I have a
... for you" pattern.

What I meant by "Cauchy" was just a ratio whose denominator's support
includes zero.  It's occasionally seen in (not so hot) dynamic
economic trade models (designed on the assumption of positive growth
rates oops :-�)P).  I don't know about other contexts.

Steve