:orphan:
# MatStructure
Indicates if two matrices have the same nonzero structure 
## Synopsis
```
typedef enum {
  DIFFERENT_NONZERO_PATTERN,
  SUBSET_NONZERO_PATTERN,
  SAME_NONZERO_PATTERN,
  UNKNOWN_NONZERO_PATTERN
} MatStructure;
```

## Values

- ***`SAME_NONZERO_PATTERN`  -*** the two matrices have identical nonzero patterns
- ***`DIFFERENT_NONZERO_PATTERN` -*** the two matrices may have different nonzero patterns
- ***`SUBSET_NONZERO_PATTERN` -*** the nonzero pattern of the second matrix is a subset of the nonzero pattern of the first matrix
- ***`UNKNOWN_NONZERO_PATTERN` -*** there is no known relationship between the nonzero patterns. In this case the implementations
may try to detect a relationship to optimize the operation





## See Also
 [](ch_matrices), `Mat`, `MatCopy()`, `MatAXPY()`, `MatAYPX()`

## Level
beginner

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

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex21.c.html">src/ksp/ksp/tutorials/ex21.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex29.c.html">src/ksp/ksp/tutorials/ex29.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex34.c.html">src/ksp/ksp/tutorials/ex34.c</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/ex77.c.html">src/ksp/ksp/tutorials/ex77.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex77f.F90.html">src/ksp/ksp/tutorials/ex77f.F90</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex79.c.html">src/ksp/ksp/tutorials/ex79.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/ksp/ksp/tutorials/ex9.c.html">src/ksp/ksp/tutorials/ex9.c</A><BR>
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/tutorials/ex9.c.html">src/mat/tutorials/ex9.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>


---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/include/petscmat.h)


[Index of all Mat routines](index.md)  
[Table of Contents for all manual pages](/manualpages/index.md)  
[Index of all manual pages](/manualpages/singleindex.md)