jbm@eos.arc.nasa.gov (Jeffrey Mulligan) (04/04/89)
Is there a way to test if a floating point variable is "NaN" or == "Inf" ? I suppose that I could always cast to integer, strip the exponent and test if the mantissa is in the legal range, but I am hoping for something more machine independent. (in case you're wondering why I care, we have an array processor which thoughtfully gives NaN for atan2(0,0). Granted, this quantity is undefined, but a legitimate value (like 0) wouldn't wreak havoc with normalization! I begin normalizing by finding the min and max; I'd like to be able to test if the min and max are NaN's!) Jeff Mulligan (jbm@aurora.arc.nasa.gov) NASA/Ames Research Ctr., Mail Stop 239-3, Moffet Field CA, 94035 (415) 694-6290 [[ I hate to say "RTFM", but.... Please see ieee_functions(3M). You will find the functions "isinf" and "isnan" documented there. --wnl ]]