Re: Simple Program, Lots of Issues (F90)

On Jul 25, 3:36=A0am, Ron Ford <r...@[EMAIL PROTECTED]
> wrote:
> On Thu, 24 Jul 2008 10:55:18 -0700 (PDT), ALevenson posted:
>
> > I just picked up Fortran yesterday at the suggestion of my mentor,
> > which for me means I glance through a tutorial and try to get a
> > program running that finds primes.

[snip]
>
> > =A0 =A0 =A0 program primes
>
> > =A0 =A0 =A0 integer :: i, j, k, l, m, n, x
> > =A0 =A0 =A0 real =A0 =A0:: t
> > =A0 =A0 =A0 logical :: notprime, even
>
> > ! Program finds primes up to
> > ! upper limit 'x' as defined by user

[snip]

> > =A0 =A0 =A0 =A0 =A0 =A0 l =3D SQRT( i )
> > =A0 =A0 =A0 =A0 =A0 =A0 do m =3D 3, l, 2
> > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0n =3D m / 2
> > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0t =3D m / 2
> > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0if ( n =3D=3D t ) then
> > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 notprime =3D 1

> Is this to be the sieve of eratosthenos?

see ftp://ftp.swcp.com/pub/walt/F/Examples/sieve.f95

The program comments are 1) in verse and 2) excerpted from a work of
science fiction. :-).

- e