topic Re: error message in using EXP function in IML. in SAS/IML Software and Matrix Computations

error message in using EXP function in IML.

ShufeGuoding — Fri, 06 Mar 2015 01:57:38 GMT

MLThe following error messages appeared in log window after running of a module in that EXP function was used in IML.

ERROR: (execution) Invalid argument to function.

count : number of occurrences is 607

operation : EXP at line 3007 column 13

operands : _TEM1013

_TEM1013 1999 rows 1 col (numeric)

Dose the error was caused by the too large argument of EXP? How to deal with that error?

Re: error message in using EXP function in IML.

Rick_SAS — Fri, 06 Mar 2015 02:02:46 GMT

I think you are probably right. If an argument is bigger than 709 then EXP overflows. You need to identify the big numbers and decide how to handle them. See the second half of the blog post "Constants in SAS" for how to prevent the overflow.

Re: error message in using EXP function in IML.

ShufeGuoding — Fri, 06 Mar 2015 02:26:47 GMT

I get it. Thanks!

Re: error message in using EXP function in IML.

Rick_SAS — Fri, 06 Mar 2015 10:52:46 GMT

You might also want to ask yourself WHY you are getting these overflows. Are you trying to evaluate a probability dentiy function (PDF) for an observation that is way out in the tail? The PDF for those observations is zero. Fitting a model to data? Maybe the model isn't appropriate for those data.