petsc-master 2015-10-05
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Sets the matrices that define the Schur complement


#include "petscksp.h" 
PetscErrorCode  MatSchurComplementSetSubMatrices(Mat S,Mat A00,Mat Ap00,Mat A01,Mat A10,Mat A11)
Collective on Mat

Input Parameter

S - matrix obtained with MatCreateSchurComplement (or equivalent) and implementing the action of A11 - A10 ksp(A00,Ap00) A01
A00,A01,A10,A11 - the four parts of A = [A00 A01; A10 A11] (A11 is optional)
Ap00 - preconditioning matrix for use in ksp(A00,Ap00) to approximate the action of A^{-1}.

Notes: The Schur complement is NOT actually formed! Rather, this object performs the matrix-vector product by using formula S = A11 - A10 A^{-1} A01 for Schur complement S and a KSP solver to approximate the action of A^{-1}.

All four matrices must have the same MPI communicator.

A00 and A11 must be square matrices.

See Also

MatCreateNormal(), MatMult(), MatCreate(), MatSchurComplementGetKSP(), MatSchurComplementUpdateSubMatrices(), MatCreateTranspose(), MatCreateSchurComplement(), MatGetSchurComplement()

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