:orphan:
# PetscSFCreateInverseSF
given a `PetscSF` in which all vertices have degree 1, creates the inverse map
## Synopsis
```
#include "petscsf.h"
PetscErrorCode PetscSFCreateInverseSF(PetscSF sf, PetscSF *isf)
```
Collective
## Input Parameter
- ***sf -*** star forest to invert
## Output Parameter
- ***isf -*** inverse of `sf`
## Notes
All roots must have degree 1.
The local space may be a permutation, but cannot be sparse.
## See Also
`PetscSF`, `PetscSFType`, `PetscSFSetGraph()`
## Level
advanced
## Location
src/vec/is/sf/interface/sf.c
## Examples
src/vec/is/sf/tutorials/ex1.c
---
[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/vec/is/sf/interface/sf.c)
[Index of all PetscSF routines](index.md)
[Table of Contents for all manual pages](/manualpages/index.md)
[Index of all manual pages](/manualpages/singleindex.md)