petsc-3.11.4 2019-09-28
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Get the individual submatrices in the Schur complement


#include "petscksp.h" 
PetscErrorCode  MatSchurComplementGetSubMatrices(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

Output Paramters

A00,A01,A10,A11 - the four parts of the original matrix A = [A00 A01; A10 A11] (A11 is optional)
Ap00 - preconditioning matrix for use in ksp(A00,Ap00) to approximate the action of A^{-1}.

Note: A11 is optional, and thus can be NULL. The submatrices are not increfed before they are returned and should not be modified or destroyed.

See Also

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




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