fortranfortran2003

Fortran 2003 does not allow this intrinsic procedure [BESSEL_J0]

I would like to use the bessel_j0 function in Fortran 2003 (the version installed on the supercomputer I use), but during the compilation of my source code I encounter the following warning:

warning #7416: Fortran 2003 does not allow this intrinsic procedure. [BESSEL_J0]

Then what?

Does it mean I cannot use it at all? Or can I call it any other way?

Solution

  • First, this is a warning, not an error. If there is nothing more following, the compilation should proceed OK.

    This kind of warning happens when you explicitly request to compile your program as Fortran 2003. So just don't that!

    Function BESSEL_J0 is from Fortran 2008. Just remove any -stand f03 or -std=f2003 or similar options. Or at least increase the standard from 03 to 08 in those flags.

    I can't more specific, because you did not tell us your compiler version and the flags you use, but the warning appears to be from Intel Fortran.