HP-MPI User's Guide (11th Edition)

Example applications
compute_pi.f
Appendix A242
C
C Collect all the partial sums.
C
call MPI_REDUCE(mypi, pi, 1, MPI_DOUBLE_PRECISION,
+ MPI_SUM, 0, MPI_COMM_WORLD, ierr)
C
C Process 0 prints the result.
C
if (myid .eq. 0) then
write(6, 97) pi, abs(pi - PI25DT)
97 format(' pi is approximately: ', F18.16,
+ ' Error is: ', F18.16)
endif
call MPI_FINALIZE(ierr)
stop
end
compute_pi output
The output from running the compute_pi executable is shown below. The
application was run with -np = 10.
Process 0 of 10 is alive
Process 1 of 10 is alive
Process 2 of 10 is alive
Process 3 of 10 is alive
Process 4 of 10 is alive
Process 5 of 10 is alive
Process 6 of 10 is alive
Process 7 of 10 is alive
Process 8 of 10 is alive
Process 9 of 10 is alive
pi is approximately: 3.1416009869231249
Error is: 0.0000083333333318