DMDASetBlockFills#

Sets the fill pattern in each block for a multi-component problem of the matrix returned by DMCreateMatrix().

Synopsis#

#include "petscdmda.h"     
PetscErrorCode DMDASetBlockFills(DM da, const PetscInt *dfill, const PetscInt *ofill)

Logically Collective

Input Parameters#

  • da - the DMDA

  • dfill - the fill pattern in the diagonal block (may be NULL, means use dense block)

  • ofill - the fill pattern in the off-diagonal blocks

Notes#

This only makes sense when you are doing multicomponent problems but using the MATMPIAIJ matrix format

The format for dfill and ofill is a 2 dimensional dof by dof matrix with 1 entries representing coupling and 0 entries for missing coupling. For example

            dfill[9] = {1, 0, 0,
                        1, 1, 0,
                        0, 1, 1}

means that row 0 is coupled with only itself in the diagonal block, row 1 is coupled with itself and row 0 (in the diagonal block) and row 2 is coupled with itself and row 1 (in the diagonal block).

DMDASetGetMatrix() allows you to provide general code for those more complicated nonzero patterns then can be represented in the dfill, ofill format

Contributed by: Glenn Hammond

See Also#

DMDA - Creating vectors for structured grids, DM, DMDA, DMCreateMatrix(), DMDASetGetMatrix(), DMSetMatrixPreallocateOnly(), DMDASetBlockFillsSparse()

Level#

developer

Location#

src/dm/impls/da/fdda.c

Index of all DMDA routines
Table of Contents for all manual pages
Index of all manual pages