PETSc version 3.17.3

MatCreateSchurComplementPmat

create a preconditioning matrix for the Schur complement by explicitly assembling the sparse matrix Sp = A11 - A10 inv(DIAGFORM(A00)) A01

Synopsis

#include "petscksp.h" 
PetscErrorCode  MatCreateSchurComplementPmat(Mat A00,Mat A01,Mat A10,Mat A11,MatSchurComplementAinvType ainvtype,MatReuse preuse,Mat *Sp)

Collective on A00

Input Parameters

	A00	- the upper-left part of the original matrix A = [A00 A01; A10 A11]
	A01	- (optional) the upper-right part of the original matrix A = [A00 A01; A10 A11]
	A10	- (optional) the lower-left part of the original matrix A = [A00 A01; A10 A11]
	A11	- (optional) the lower-right part of the original matrix A = [A00 A01; A10 A11]
	ainvtype	- type of approximation for DIAGFORM(A00) used when forming Sp = A11 - A10 inv(DIAGFORM(A00)) A01. See MatSchurComplementAinvType.
	preuse	- MAT_INITIAL_MATRIX for a new Sp, or MAT_REUSE_MATRIX to reuse an existing Sp, or MAT_IGNORE_MATRIX to put nothing in Sp

Output Parameter

- approximate Schur complement suitable for preconditioning the true Schur complement S = A11 - A10 inv(A00) A01

Level

advanced

Location