How to detect NaN's

[Vic Rice]

I have encountered a problem on a DECStation 5000 using the Mips Fortran
compiler. Some operation I am performing is generating a NaN which then
proceeds to propogate to other dependent variables. Since this is in
a loop, I am not exactly sure where it starts.

How can I test a variable for the presence of a NaN or Infinity ???
-- 
Dr. Victor L. Rice
Litwin Process Automation