petsc-3.12.5 2020-03-29

ISGetIndices

Returns a pointer to the indices. The user should call ISRestoreIndices() after having looked at the indices. The user should NOT change the indices.

#include "petscis.h" 
PetscErrorCode  ISGetIndices(IS is,const PetscInt *ptr[])

Not Collective

is -the index set

ptr -the location to put the pointer to the indices

This routine has two different interfaces from Fortran; the first is not recommend, it does not require Fortran 90

   IS          is

   integer     is_array(1)

   PetscOffset i_is

   int         ierr

      call ISGetIndices(is,is_array,i_is,ierr)

  Access first local entry in list

     value = is_array(i_is + 1)

     ...... other code

      call ISRestoreIndices(is,is_array,i_is,ierr)

The second Fortran interface is recommended.

         use petscisdef

         PetscInt, pointer :: array(:)

         PetscErrorCode  ierr

         IS       i

         call ISGetIndicesF90(i,array,ierr)

See the Fortran chapter of the users manual and petsc/src/is/examples/[tutorials,tests] for details.

intermediate