what i thought was variance
is actually std deviation.
eep. so i had to run right off and change variable names.

other: dave says that he shared my "poisson looks funny" intuition, but that
       (in the code that i stole) it is doing the right thing (can't make any
       promises yet about the code after i glued it in)

i have to take a good careful look at the argcount manipulation code.