:orphan:
# MatSetValuesLocal
Inserts or adds values into certain locations of a matrix, using a local numbering of the nodes. 
## Synopsis
```
#include "petscmat.h" 
PetscErrorCode MatSetValuesLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], const PetscScalar y[], InsertMode addv)
```
Not Collective


## Input Parameters

- ***mat -*** the matrix
- ***nrow -*** number of rows
- ***irow -*** the row local indices
- ***ncol -*** number of columns
- ***icol -*** the column local indices
- ***y -*** a logically two-dimensional array of values
- ***addv -*** either `INSERT_VALUES` to add values to any existing entries, or `INSERT_VALUES` to replace existing entries with new values





## Notes
If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call MatXXXXSetPreallocation() or
`MatSetUp()` before using this routine

If you create the matrix yourself (that is not with a call to `DMCreateMatrix()`) then you MUST call `MatSetLocalToGlobalMapping()` before using this routine

Calls to `MatSetValuesLocal()` with the `INSERT_VALUES` and `ADD_VALUES`
options cannot be mixed without intervening calls to the assembly
routines.

These values may be cached, so `MatAssemblyBegin()` and `MatAssemblyEnd()`
MUST be called after all calls to `MatSetValuesLocal()` have been completed.


## Developer Note
This is labeled with C so does not automatically generate Fortran stubs and interfaces
because it requires multiple Fortran interfaces depending on which arguments are scalar or arrays.


## See Also
 [](ch_matrices), `Mat`, `MatAssemblyBegin()`, `MatAssemblyEnd()`, `MatSetValues()`, `MatSetLocalToGlobalMapping()`,
`MatGetValuesLocal()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/interface/matrix.c.html#MatSetValuesLocal">src/mat/interface/matrix.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex35.cxx.html">src/ksp/ksp/tutorials/ex35.cxx</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex36.cxx.html">src/ksp/ksp/tutorials/ex36.cxx</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex70.c.html">src/ksp/ksp/tutorials/ex70.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex14.c.html">src/snes/tutorials/ex14.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex28.c.html">src/snes/tutorials/ex28.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex35.c.html">src/snes/tutorials/ex35.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex40f90.F90.html">src/snes/tutorials/ex40f90.F90</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex46.c.html">src/snes/tutorials/ex46.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex5.c.html">src/snes/tutorials/ex5.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex55.c.html">src/snes/tutorials/ex55.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex5f.F90.html">src/snes/tutorials/ex5f.F90</A><BR>

## Implementations

<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/is/matis.c.html#MatSetValuesLocal_IS">MatSetValuesLocal_IS in src/mat/impls/is/matis.c</A><BR>


---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/mat/interface/matrix.c)


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