sqrt(NaN)

[tropfen]

Hello,

looking inside old threads if have found many comments on how to produce a NaN using sqrt().

I have a question about what should happen based on fortran standard with

sqrt(NaN)

In CVF 6.6 it is an error. In IVF 10.1.026 it is no error.

Thanks in advance.

Frank

[Steven_L_Intel1]

The Fortran standard does not define the result. With IVF, I would expect that you get a NaN result. A run-time error might occur if you used /fpe:0.

[tropfen]

Quoting - Steve Lionel (Intel)

The Fortran standard does not define the result. With IVF, I would expect that you get a NaN result. A run-time error might occur if you used /fpe:0.

Hello,

to be honest, I was afraid to get this kind of answer. In the last weeks and months i had to read quite often a reply like: you have to set this /xxx: yyyy.

For me sending a NaN into a call like sqrt has to produce an error in the standard configuration of IVF. Sending in an NaN and getting back a NaN is not normal behavior.

May be I have lost contact to modern programming.

Frank

[Steven_L_Intel1]

The normal behavior for operations on NaNs in IEE floating point is to result in a NaN.