Example: PI in Fortran - 2

call MPI_BCAST( n, 1, MPI_INTEGER, 0, + MPI_COMM_WORLD, ierr) c check for quit signal if ( n .le. 0 ) goto 30 c calculate the interval size h = 1.0d0/n sum = 0.0d0 do 20 i = myid+1, n, numprocs x = h * (dble(i) - 0.5d0) sum = sum + f(x) 20 continue mypi = h * sum c collect all the partial sums call MPI_REDUCE( mypi, pi, 1, MPI_DOUBLE_PRECISION, + MPI_SUM, 0, MPI_COMM_WORLD,ierr)