petsc-3.10.5 2019-03-28
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# PCASMGetLocalSubmatrices

Gets the local submatrices (for this processor only) for the additive Schwarz preconditioner.

### Synopsis

    #include "petscpc.h"
    PetscErrorCode  PCASMGetLocalSubmatrices(PC pc,PetscInt *n,Mat *mat[])

Not Collective

### Input Parameter

pc -the preconditioner context

### Output Parameters

| n | - the number of matrices for this processor (default value = 1)
| mat | - the matrices

### Notes

Call after PCSetUp() (or KSPSetUp()) but before PCApply() (or KSPApply()) and before PCSetUpOnBlocks())

Usually one would use PCSetModifySubmatrices() to change the submatrices in building the preconditioner.

### Keywords

PC, ASM, set, local, subdomains, additive Schwarz, block Jacobi

### See Also

PCASMSetTotalSubdomains(), PCASMSetOverlap(), PCASMGetSubKSP(),
PCASMCreateSubdomains2D(), PCASMSetLocalSubdomains(), PCASMGetLocalSubdomains(), PCSetModifySubmatrices()

### Level

advanced

### Location

src/ksp/pc/impls/asm/asm.c
Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages