petsc-3.14.6 2021-03-30
MatSchurComplementSetSubMatrices
Sets the matrices that define the Schur complement
Synopsis
#include "petscksp.h"
PetscErrorCode MatSchurComplementSetSubMatrices(Mat S,Mat A00,Mat Ap00,Mat A01,Mat A10,Mat A11)
Collective on S
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()
Level
intermediate
Location
src/ksp/ksp/utils/schurm/schurm.c
Index of all KSP routines
Table of Contents for all manual pages
Index of all manual pages