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 10: PetscErrorCode ierr 11: PetscInt f(1) 12: PetscCallA(PetscInitialize(ierr)) 13: f(1) = 1 14: PetscCallMPIA(MPI_Allreduce(MPI_IN_PLACE,f,1,MPIU_INTEGER,MPI_MIN,PETSC_COMM_WORLD,ierr)) 15: PetscCallA(PetscFinalize(ierr)) 16: end 18: !/*TEST 19: ! 20: ! test: 21: ! 22: !TEST*/