:orphan: # SNESFASSetInterpolation Sets the `Mat` to be used to apply the interpolation from l-1 to the lth level ## Synopsis ``` #include "petscsnes.h" PetscErrorCode SNESFASSetInterpolation(SNES snes, PetscInt level, Mat mat) ``` ## Input Parameters - ***snes -*** the `SNESFAS` nonlinear multigrid context - ***mat -*** the interpolation operator - ***level -*** the level (0 is coarsest) to supply [do not supply 0] ## Notes Usually this is the same matrix used also to set the restriction for the same level. One can pass in the interpolation matrix or its transpose; PETSc figures out from the matrix size which one it is. ## See Also `SNESFAS`, `SNESFASSetInjection()`, `SNESFASSetRestriction()`, `SNESFASSetRScale()` ## Level advanced ## Location src/snes/impls/fas/fasfunc.c --- [Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/snes/impls/fas/fasfunc.c) [Index of all SNESFAS routines](index.md) [Table of Contents for all manual pages](/manualpages/index.md) [Index of all manual pages](/manualpages/singleindex.md)