petsc-3.4.2 2013-07-02

# MatSchurComplementSet

Sets the matrices that define the Schur complement

### Synopsis

    #include "petscksp.h"
    PetscErrorCode  MatSchurComplementSet(Mat N,Mat A00,Mat Ap00,Mat A01,Mat A10,Mat A11)

Collective on Mat

### Input Parameter

| N | - matrix obtained with MatCreate() and MatSetType(MATSCHURCOMPLEMENT);
| A00,A01,A10,A11 | - the four parts of the original matrix (A00 is optional)

Notes: The Schur complement is NOT actually formed! Rather this object performs the matrix-vector product by using the the formula for the Schur complement and a KSP solver to approximate the action of inv(A)

All four matrices must have the same MPI communicator

A00 and A11 must be square matrices

### See Also

MatCreateNormal(), MatMult(), MatCreate(), MatSchurComplementGetKSP(), MatSchurComplementUpdate(), MatCreateTranspose(), MatGetSchurComplement()

Level:intermediate
Location: src/ksp/ksp/utils/schurm.c
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages