# ISAllGatherColors
Given a a set of colors on each processor, generates a large set (same on each processor) by concatenating together each processors colors 
## Synopsis
```
#include "petscis.h"  
PetscErrorCode ISAllGatherColors(MPI_Comm comm, PetscInt n, ISColoringValue *lindices, PetscInt *outN, ISColoringValue *outindices[])
```
Collective


## Input Parameters

- ***comm -*** communicator to share the indices
- ***n -*** local size of set
- ***lindices -*** local colors



## Output Parameters

- ***outN -*** total number of indices
- ***outindices -*** all of the colors





## Note
`ISAllGatherColors()` is clearly not scalable for large index sets.


## See Also
 `ISCOloringValue`, `ISColoring()`, `ISCreateGeneral()`, `ISCreateStride()`, `ISCreateBlock()`, `ISAllGather()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/vec/is/is/utils/iscoloring.c.html#ISAllGatherColors">src/vec/is/is/utils/iscoloring.c</A>


---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/vec/is/is/utils/iscoloring.c)


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