Programming/Fortran

From HPC
Revision as of 14:03, 17 March 2017 by Pysdlb (talk | contribs)

Jump to: navigation , search

Programming Details

Fortran (formerly FORTRAN, derived from Formula Translation) is a general-purpose, imperative programming language that is especially suited to numeric computation and scientific computing.

Icon tick.png There is direct support for openMP and openMPI.

Programming example

Non Parallel Example

program variableTesting
implicit none

   ! declaring variables
   integer :: total,average
   complex :: cx
   logical :: done
   character(len=80) :: message ! a string of 80 characters

   !assigning values
   total = 20000
   average = 1666
   done = .true.
   message = "A big Hello from HPC"

   cx = (3.0, 5.0) ! cx = 3.0 + 5.0i

        if (total .ge. average) then
                print *, total, " greater or equal than average"
        else
                print *, total, " less than average"
        endif

   Print *, average
   Print *, cx
   Print *, done
   Print *, message

end program variableTesting

Parallel Example (openMP)

program helloworld
  use omp_lib
  implicit none

!$OMP PARALLEL
!$OMP CRITICAL
  print *,'Hello from thread number',OMP_GET_THREAD_NUM()
!$OMP END CRITICAL
!$OMP END PARALLEL

end program helloworld

Modules Available

The following modules are available:

  • module add gcc/4.9.3 (GNU compiler)
  • module add intel/compiler/64/2016.2.181 (Intel compiler)

Compilation

The program would be compiled in the following way, optional Intel compiler available too:

[username@login01 ~]$  module add gcc/4.9.3
[username@login01 ~]$  gfortran -o testFortran  testFortran.f03

Usage Examples

Batch example


#!/bin/bash

#SBATCH -J openmpi-single-node
#SBATCH -N 1
#SBATCH --ntasks-per-node 28
#SBATCH -o %N.%j.%a.out
#SBATCH -e %N.%j.%a.err
#SBATCH -p compute
#SBATCH --exclusive

echo $SLURM_JOB_NODELIST

module purge
module add gcc/4.9.3

export I_MPI_DEBUG=5
export I_MPI_FABRICS=shm:tmi
export I_MPI_FALLBACK=no

/home/user/CODE_SAMPLES/OPENMP/demo
[username@login01 ~]$ sbatch demo.job
Submitted batch job 239552

Further Information

Icon home.png Programming support