PCSetModifySubMatrices#
Sets a user-defined routine for modifying the submatrices that arise within certain subdomain-based preconditioners such as PCASM
Synopsis#
#include "petscksp.h"
PetscErrorCode PCSetModifySubMatrices(PC pc, PetscErrorCode (*func)(PC pc, PetscInt nsub, const IS row[], const IS col[], Mat submat[], void *ctx), void *ctx)
Logically Collective
Input Parameters#
pc - the preconditioner context
func - routine for modifying the submatrices
ctx - optional user-defined context (may be
NULL)
Calling sequence of func#
pc - the preconditioner context
nsub - number of index sets
row - an array of index sets that contain the global row numbers that comprise each local submatrix
col - an array of index sets that contain the global column numbers that comprise each local submatrix
submat - array of local submatrices
ctx - optional user-defined context for private data for the user-defined func routine (may be
NULL)
Notes#
The basic submatrices are extracted from the preconditioner matrix as usual; the user can then alter these (for example, to set different boundary conditions for each submatrix) before they are used for the local solves.
PCSetModifySubMatrices() MUST be called before KSPSetUp() and
KSPSolve().
A routine set by PCSetModifySubMatrices() is currently called within
the block Jacobi (PCBJACOBI) and additive Schwarz (PCASM)
preconditioners. All other preconditioners ignore this routine.
See Also#
KSP: Linear System Solvers, PC, PCBJACOBI, PCASM, PCModifySubMatrices()
Level#
advanced
Location#
Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages