/*@
AOApplicationToPetscIS - Maps an index set in the application-defined
ordering to the PETSc ordering.
Collective on AO and IS
Input Parameters:
+ ao - the application ordering context
- is - the index set; this is replaced with its mapped values
Output Parameter:
. is - the mapped index set
Level: beginner
Note:
The index set cannot be of type stride or block
Any integers in ia[] that are negative are left unchanged. This
allows one to convert, for example, neighbor lists that use negative
entries to indicate nonexistent neighbors due to boundary conditions, etc.
.keywords: application ordering, mapping
.seealso: AOCreateBasic(), AOView(), AOPetscToApplication(),
AOPetscToApplicationIS(), AOApplicationToPetsc()
@*/
PetscErrorCode AOApplicationToPetscIS(AO ao,IS is)
{
PetscErrorCode ierr;
PetscInt n,*ia;
PetscFunctionBegin;
PetscValidHeaderSpecific(ao,AO_CLASSID,1);
PetscValidHeaderSpecific(is,IS_CLASSID,2);
ierr = ISToGeneral(is);CHKERRQ(ierr);
/* we cheat because we know the is is general and that we can change the indices */
ierr = ISGetIndices(is,(const PetscInt**)&ia);CHKERRQ(ierr);
ierr = ISGetLocalSize(is,&n);CHKERRQ(ierr);
ierr = (*ao->ops->applicationtopetsc)(ao,n,ia);CHKERRQ(ierr);
ierr = ISRestoreIndices(is,(const PetscInt**)&ia);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
int main(int argc,char **argv)
{
PetscErrorCode ierr;
PetscInt step = 2;
IS is;
ierr = PetscInitialize(&argc,&argv,(char*)0,help);CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,"-step",&step,NULL);CHKERRQ(ierr);
ierr = ISCreateStride(PETSC_COMM_SELF,10,0,step,&is);CHKERRQ(ierr);
ierr = ISToGeneral(is);CHKERRQ(ierr);
ierr = ISDestroy(&is);CHKERRQ(ierr);
ierr = PetscFinalize();
return 0;
}
void PETSC_STDCALL istogeneral_(IS is, int *__ierr ){
*__ierr = ISToGeneral(
(IS)PetscToPointer((is) ));
}
