petsc-3.6.2 2015-10-02
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Sets whether it computes the ||U|| used by the WP PETSc routine for computing h. With any Krylov solver this need only be computed during the first iteration and kept for later.


#include "petscmat.h"   
PetscErrorCode  MatMFFDWPSetComputeNormU(Mat A,PetscBool flag)

Input Parameters

A - the matrix created with MatCreateSNESMF()
flag - PETSC_TRUE causes it to compute ||U||, PETSC_FALSE uses the previous value

Options Database Key

-mat_mffd_compute_normu <true,false> -true by default, false can save calculations but you must be sure that ||U|| has not changed in the mean time.


See the manual page for MATMFFD_WP for a complete description of the algorithm used to compute h.

See Also

MatMFFDSetFunctionError(), MatCreateSNESMF()

Index of all Mat routines
Table of Contents for all manual pages
Index of all manual pages