KSPGetOperators — PETSc 3.23.0 documentation

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# KSPGetOperators

Gets the matrix associated with the linear system and a (possibly) different one used to construct the preconditioner from the `KSP` context

## Synopsis

    #include "petscksp.h"
    PetscErrorCode KSPGetOperators(KSP ksp, Mat *Amat, Mat *Pmat)

Collective

## Input Parameter

- ksp - the `KSP` context

## Output Parameters

- Amat - the matrix that defines the linear system

- Pmat - the matrix to be used in constructing the preconditioner, usually the same as `Amat`.

## Notes

If `KSPSetOperators()` has not been called then the `KSP` object will attempt to automatically create the matrix `Amat` and return it

Use `KSPGetOperatorsSet()` to determine if matrices have been provided.

DOES NOT increase the reference counts of the matrix, so you should NOT destroy them.

## See Also

KSP: Linear System Solvers, `KSP`, `KSPSolve()`, `KSPGetPC()`, `PCSetOperators()`, `KSPSetOperators()`, `KSPGetOperatorsSet()`

## Level

intermediate

## Location

src/ksp/ksp/interface/itcreate.c

## Examples

src/ksp/ksp/tutorials/ex59.c
src/ksp/ksp/tutorials/ex42.c
src/ksp/ksp/tutorials/ex45.c
src/ksp/ksp/tutorials/ex25.c
src/ksp/ksp/tutorials/ex27.c
src/ksp/ksp/tutorials/ex56.c
src/ksp/ksp/tutorials/ex34.c

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