# MatSetValue
Set a single entry into a matrix. Not collective


## Synopsis
```
#include <petscmat.h>
PetscErrorCode MatSetValue(Mat m,PetscInt row,PetscInt col,PetscScalar value,InsertMode mode)
```

## Input Parameters

- ***m -*** the matrix
- ***row -*** the row location of the entry
- ***col -*** the column location of the entry
- ***value -*** the value to insert
- ***mode -*** either `INSERT_VALUES` or `ADD_VALUES`



## Notes
For efficiency one should use `MatSetValues()` and set several values simultaneously.




## See Also
 `MatGetValue()`, `MatSetValues()`, `MatSetValueLocal()`, `MatSetValuesLocal()`

## Level
beginner

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/include/petscmat.h.html#MatSetValue">include/petscmat.h</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/tutorials/ex4.c.html">src/mat/tutorials/ex4.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/tutorials/ex4f.F90.html">src/mat/tutorials/ex4f.F90.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex21.c.html">src/ksp/ksp/tutorials/ex21.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex27.c.html">src/ksp/ksp/tutorials/ex27.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex4.c.html">src/ksp/ksp/tutorials/ex4.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex44f.F90.html">src/ksp/ksp/tutorials/ex44f.F90.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex59.c.html">src/ksp/ksp/tutorials/ex59.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex61f.F90.html">src/ksp/ksp/tutorials/ex61f.F90.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex73.c.html">src/ksp/ksp/tutorials/ex73.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex76.c.html">src/ksp/ksp/tutorials/ex76.c.html</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/snes/tutorials/ex47cu.cu.html">src/snes/tutorials/ex47cu.cu.html</A><BR>


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