:orphan:
# MatDuplicateOption
Indicates if a duplicated sparse matrix should have its numerical values copied over or just its nonzero structure. 
## Synopsis
```
typedef enum {
  MAT_DO_NOT_COPY_VALUES,
  MAT_COPY_VALUES,
  MAT_SHARE_NONZERO_PATTERN
} MatDuplicateOption;
```

## Values

- ***`MAT_DO_NOT_COPY_VALUES`    -*** Create a matrix using the same nonzero pattern as the original matrix,
with zeros for the numerical values
- ***`MAT_COPY_VALUES`           -*** Create a matrix with the same nonzero pattern as the original matrix
and with the same numerical values.
- ***`MAT_SHARE_NONZERO_PATTERN` -*** Create a matrix that shares the nonzero structure with the previous matrix
and does not copy it, using zeros for the numerical values. The parent and
child matrices will share their index (i and j) arrays, and you cannot
insert new nonzero entries into either matrix





## Note
Many matrix types (including `MATSEQAIJ`) do not support the `MAT_SHARE_NONZERO_PATTERN` optimization; in
this case the behavior is as if `MAT_DO_NOT_COPY_VALUES` has been specified.


## See Also
 [](ch_matrices), `Mat`, `MatDuplicate()`

## Level
beginner

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

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex42.c.html">src/ksp/ksp/tutorials/ex42.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex5.c.html">src/ksp/ksp/tutorials/ex5.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex5f.F90.html">src/ksp/ksp/tutorials/ex5f.F90</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex76.c.html">src/ksp/ksp/tutorials/ex76.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex81.c.html">src/ksp/ksp/tutorials/ex81.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/pde_constrained/tutorials/elliptic.c.html">src/tao/pde_constrained/tutorials/elliptic.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/pde_constrained/tutorials/hyperbolic.c.html">src/tao/pde_constrained/tutorials/hyperbolic.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/pde_constrained/tutorials/parabolic.c.html">src/tao/pde_constrained/tutorials/parabolic.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/tutorials/ex4.c.html">src/tao/tutorials/ex4.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/unconstrained/tutorials/burgers_spectral.c.html">src/tao/unconstrained/tutorials/burgers_spectral.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/unconstrained/tutorials/spectraladjointassimilation.c.html">src/tao/unconstrained/tutorials/spectraladjointassimilation.c</A><BR>


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