Hi, I'm a newcomer to programming! I'm using two compilers to compile exactly the same fortran 90 program. I'm using gfortran and visual fortran (shame on me!). The thing is that the numeric results I get with these two different compilers start differing from the 7th decimal digit. Could anybody explain me why does this happen? I use double precision numbers. Salomon ___________________________________________________________ Do You Yahoo!? La mejor conexión a Internet y <b >2GB</b> extra a tu correo por $100 al mes. http://net.yahoo.com.mx