Introduction to HPC

High Performance Computing 1

Timing

COMPUTEPI.f

program main

include "mpif.h"

double precision PI25DT

parameter (PI25DT =3.141592653589793238462643d0)

double precision mypi, pi, h, sum, x, f, a

double precision starttime, endtime

integer n, myid, numprocs, i, ierr

c function to integrate

f(a) = 4.d0 / (1.d0 + a*a)

call MPI_INIT(ierr)

call MPI_COMM_RANK(MPI_COMM_WORLD, myid, ierr)

call MPI_COMM_SIZE(MPI_COMM_WORLD, numprocs, ierr)

10if ( myid .eq. 0 ) then

print *, 'Enter the number of intervals: (0 quits) '

read(*,*) n

endif