:orphan:
# TaoGetDualVariables
Gets the dual vectors 
## Synopsis
```
#include "petsctao.h" 
PetscErrorCode TaoGetDualVariables(Tao tao, Vec *DE, Vec *DI)
```
Collective


## Input Parameter

- ***tao -*** the `Tao` context



## Output Parameters

- ***DE -*** dual variable vector for the lower bounds
- ***DI -*** dual variable vector for the upper bounds





## See Also
 [](ch_tao), `Tao`, `TaoComputeDualVariables()`

## Level
advanced

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/interface/taosolver_bounds.c.html#TaoGetDualVariables">src/tao/interface/taosolver_bounds.c</A>

## Examples
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/tao/constrained/tutorials/ex1.c.html">src/tao/constrained/tutorials/ex1.c</A><BR>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/tao/interface/taosolver_bounds.c)


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