The MOD function

The intrinsic function MOD in Fortran takes two integer arguments, which should both be of the same type. This means that it may be necessary to cast the arguments to, e.g. INT for some architectures. This can occur in particular when a CCTK_INT parameter and the Cactus variable cctk_iteration (which is declared to be INTEGER) are used, in which case the correct code is

MOD(cctk_iteration,INT(MyParameter))