Programming/Fortran
From HPC
Contents
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.
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 load gcc/4.9.3 (GNU compiler)
- module load 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 load 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 $SLURM_JOB_NODELIST module purge module load gcc/4.9.3 export I_MPI_DEBUG=5 export I_MPI_FABRICS=shm:tmi export I_MPI_FALLBACK=no /home/user/CODE_SAMPLES/OPENMP/demo
[username@login01 ~]$ sbatch demo.job Submitted batch job 239552