# MATSOLVERBAS
Provides ICC(k) with drop tolerance Works with `MATAIJ`  matrices


## Options Database Keys

- ***-pc_factor_levels <l> -*** number of levels of fill
- ***-pc_factor_drop_tolerance -*** is not currently hooked up to do anything




Contributed by: Bas van 't Hof


## Note
Since this currently hooked up to use drop tolerance it should produce the same factors and hence convergence as the PETSc ICC, for higher
levels of fill it does not. This needs to be investigated. Unless you are interested in drop tolerance ICC and willing to work through the code
we recommend not using this functionality.


## See Also
 `PCFactorSetMatSolverType()`, `MatSolverType`, `PCFactorSetLevels()`, `PCFactorSetDropTolerance()`

## Level
intermediate

## Location
<A HREF="PETSC_DOC_OUT_ROOT_PLACEHOLDER/src/mat/impls/aij/seq/bas/spbas.c.html#MATSOLVERBAS">src/mat/impls/aij/seq/bas/spbas.c</A>


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[Edit on GitLab](https://gitlab.com/petsc/petsc/-/edit/release/src/mat/impls/aij/seq/bas/spbas.c)


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