:orphan:
# TaoADMMSetMisfitHessianRoutine
Sets the user-defined misfit Hessian call-back function into the algorithm, to be used for subsolverX.
## Synopsis
```
#include "petsctao.h"
PetscErrorCode TaoADMMSetMisfitHessianRoutine(Tao tao, Mat H, Mat Hpre, PetscErrorCode (*func)(Tao, Vec, Mat, Mat, void *), void *ctx)
```
Collective
## Input Parameters
- ***tao -*** the `Tao` context
- ***H -*** user-created matrix for the Hessian of the misfit term
- ***Hpre -*** user-created matrix for the preconditioner of Hessian of the misfit term
- ***func -*** function pointer for the misfit Hessian evaluation
- ***ctx -*** user context for the misfit Hessian
## See Also
`TAOADMM`
## Level
advanced
## Location
src/tao/constrained/impls/admm/admm.c
## Examples
src/tao/constrained/tutorials/tomographyADMM.c
---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/tao/constrained/impls/admm/admm.c)
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