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DanRRight · Posted: Wed Dec 03, 2025 11:51 am Post subject: If variable is NaN ...

I do not remember FTN95 had NaN before.

I got corruption on harddrive or SSD (being lazy to do the entire disk formatting with check - this takes way too long now, a week or so). As a results computer trying to recover the data had read them as NAN and denormals.

How best to write IF statement to exclude them from consideration in the code?

PaulLaidler · Posted: Wed Dec 03, 2025 1:13 pm Post subject:

Version 9.10 of FTN95 supports the intrinsic module IEEE_ARITHMETIC which means that Fortran 2003 intrinsics such as IEEE_IS_NAN are available when you "USE IEEE_ARITHMETIC".

DanRRight · Posted: Sat Dec 06, 2025 3:03 pm Post subject:

Thanks, I briefly looked at that fortran 2003 NaN stuff and seems all is clear there. Also are denormal numbers treated there the same way ?

I remember FTN95 had some protective measures against denormals even way before F2003 and I used tricks against of them, if I am not mixing these with something they were like this below. I do not using them now for a long time.