# ReductionType
determines what type of column reduction (one that is not a type of norm defined in `NormType`) to compute 
## Synopsis
```
/* NOTE: The integer constants defined in ReductionType MUST BE DISTINCT from those defined in NormType.
 * This is because MatGetColumnReductions() is used to compute both norms and other types of reductions,
 * and the constants defined in both NormType and ReductionType are used to designate the desired operation. */typedef enum {
  REDUCTION_SUM_REALPART       = 10,
  REDUCTION_MEAN_REALPART      = 11,
  REDUCTION_SUM_IMAGINARYPART  = 12,
  REDUCTION_MEAN_IMAGINARYPART = 13
} ReductionType;
```



## See Also
 `MatGetColumnReductions()`, `MatGetColumnNorms()`, `NormType`

## Level
beginner

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/include/petscvec.h.html#ReductionType">include/petscvec.h</A>


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


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