petsc-master 2014-09-18
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PCSetModifySubMatrices

Sets a user-defined routine for modifying the submatrices that arise within certain subdomain-based preconditioners. 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.

Synopsis

#include "petscksp.h" 
PetscErrorCode  PCSetModifySubMatrices(PC pc,PetscErrorCode (*func)(PC,PetscInt,const IS[],const IS[],Mat[],void*),void *ctx)
Logically Collective on PC

Input Parameters

pc - the preconditioner context
func - routine for modifying the submatrices
ctx - optional user-defined context (may be null)

Calling sequence of func

    func (PC pc,PetscInt nsub,IS *row,IS *col,Mat *submat,void *ctx);

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

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.

Keywords

PC, set, modify, submatrices

See Also

PCModifySubMatrices(), PCASMGetSubMatrices()

Level:advanced
Location:
src/ksp/pc/interface/precon.c
Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages