Hallo I have a code for shallow water equations written in Fortran. there is the option "promote real to double precision" with visual fortran?Because my variables are declared as:

REAL NAME1,NAME2,NAME3

and I want just to compile sometimes in single and simetimes in double precision just changing the option without change the code thanks so much Alberto

u can use this method !

parameter (n=4)

real(n) name1, .....

if you use modul for data base of variables it will be very easy. it needs to chaing only in main module of your data base

module var_database

parameter (n=4) 'or n=8'

real(n) name1, .....

real(n) name3, .....

end module ... . . .

subroutine sub1

use var_database

end sub1