# TaoALMMGetPrimalIS
Retrieve a pointer to the index set that identifies optimization and slack variable components of the subsolver's solution vector. Not valid for problems with only equality constraints. 
## Synopsis
```
#include "petsctao.h" 
#include "petscvec.h" 
PetscErrorCode TaoALMMGetPrimalIS(Tao tao, IS *opt_is, IS *slack_is)
```

## Input Parameter

- ***tao -*** the `Tao` context for the `TAOALMM` solver



## Output Parameters

- ***opt_is -*** index set associated with the optimization variables (NULL if not needed)
- ***slack_is -*** index set associated with the slack variables (NULL if not needed)





## See Also
 `TAOALMM`, `Tao`, `IS`, `TaoALMMGetPrimalVector()`

## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/constrained/impls/almm/almmutils.c.html#TaoALMMGetPrimalIS">src/tao/constrained/impls/almm/almmutils.c</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/tao/constrained/impls/almm/almmutils.c)


[Index of all Tao routines](index.md)  
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