static char help[] = "Tests I/O of vectors for different data formats (binary,HDF5) and illustrates the use of user-defined event logging\n\n";

#include <petscvec.h>
#include <petscviewerhdf5.h>

 int main(int argc,char **args)
{
  PetscErrorCode    ierr;
  PetscMPIInt       rank,size;
  PetscInt          i,m = 268435456,low,high,ldim,iglobal,lsize;
  PetscScalar       v;
  Vec               u;
  PetscViewer       viewer;

  ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr;
  ierr = PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL);CHKERRQ(ierr);

 /* Generate vector */
  ierr = VecCreate(PETSC_COMM_WORLD,&u);CHKERRQ(ierr);
  ierr = PetscObjectSetName((PetscObject)u, "ref_index");CHKERRQ(ierr);
  
  ierr = VecSetSizes(u,PETSC_DECIDE,m);CHKERRQ(ierr);
  ierr = VecSetFromOptions(u);CHKERRQ(ierr);
  ierr = VecGetOwnershipRange(u,&low,&high);CHKERRQ(ierr);
  ierr = VecGetLocalSize(u,&ldim);CHKERRQ(ierr);
  
  for (i=0; i<ldim; i++) {
    iglobal = i + low;
    v       = (PetscScalar)(i + low);
    ierr    = VecSetValues(u,1,&iglobal,&v,INSERT_VALUES);CHKERRQ(ierr);
  }
  ierr = VecAssemblyBegin(u);CHKERRQ(ierr);
  ierr = VecAssemblyEnd(u);CHKERRQ(ierr);
  
  ierr = PetscPrintf(PETSC_COMM_WORLD,"writing vector in hdf5 ...\n");CHKERRQ(ierr);
  ierr = PetscViewerHDF5Open(PETSC_COMM_WORLD,"ref_index_ms.h5",FILE_MODE_WRITE,&viewer);CHKERRQ(ierr);
  ierr = VecView(u,viewer);
  ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);

 /* Free data structures */
  ierr = VecDestroy(&u);CHKERRQ(ierr);
  ierr = PetscFinalize();
  return ierr;
}