petsc-3.8.4 2018-03-24

DMCompositeGetLocalISs

Gets index sets for each component of a composite local vector

Synopsis

#include "petscdmcomposite.h"  
PetscErrorCode  DMCompositeGetLocalISs(DM dm,IS **is)

Not Collective

Input Arguments

dm -composite DM

Output Arguments

is -array of serial index sets for each each component of the DMComposite

Notes

At present, a composite local vector does not normally exist. This function is used to provide index sets for MatGetLocalSubMatrix(). In the future, the scatters for each entry in the DMComposite may be be merged into a single scatter to a composite local vector. The user should not typically need to know which is being done.

To get the composite global indices at all local points (including ghosts), use DMCompositeGetISLocalToGlobalMappings().

To get index sets for pieces of the composite global vector, use DMCompositeGetGlobalISs().

Each returned IS should be destroyed with ISDestroy(), the array should be freed with PetscFree().

Examples