#include "petscmat.h" PetscErrorCode MatFactorGetSchurComplement(Mat F,Mat* S,MatFactorSchurStatus* status)Logically Collective on Mat
|F||- the factored matrix obtained by calling MatGetFactor()|
|*S||- location where to return the Schur complement, can be NULL|
|status||- the status of the Schur complement matrix, can be NULL|
Schur complement mode is currently implemented for sequential matrices. The routine returns a the Schur Complement stored within the data strutures of the solver. If MatFactorInvertSchurComplement() has previously been called, the returned matrix is actually the inverse of the Schur complement. The returned matrix should not be destroyed; the caller should call MatFactorRestoreSchurComplement() when the object is no longer needed.
Use MatFactorCreateSchurComplement() to create a copy of the Schur complement matrix that is within a factored matrix
See MatCreateSchurComplement() or MatGetSchurComplement() for ways to create virtual or approximate Schur complements.