- the factored matrix obtained by calling MatGetFactor()
*S
- location where to return the Schur complement (in MATDENSE format)
Notes
Schur complement mode is currently implemented for sequential matrices.
The routine returns a dense matrix pointing to the raw data of the Schur Complement stored within the data strutures of the solver; e.g. if MatFactorInvertSchurComplement has been called, the returned matrix is actually the inverse of the Schur complement.
The caller should call MatFactorRestoreSchurComplement when the object is no longer needed.