1! 2! Simple PETSc Program written in Fortran 3! 4 program main 5#include <petsc/finclude/petscsys.h> 6 use petscmpi ! or mpi or mpi_f08 7 use petscsys 8 implicit none 9 10 PetscErrorCode ierr 11 PetscInt f(1) 12 call PetscInitialize(PETSC_NULL_CHARACTER,ierr) 13 if (ierr .ne. 0) then 14 print*, 'Unable to begin PETSc program' 15 endif 16 17 f(1) = 1 18 call MPI_Allreduce(MPI_IN_PLACE,f,1,MPIU_INTEGER,MPI_MIN,PETSC_COMM_WORLD,ierr) 19 call PetscFinalize(ierr) 20 end 21 22!/*TEST 23! 24! test: 25! 26!TEST*/ 27