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 "petscsnes.h"   
PetscErrorCode PETSCSNES_DLLEXPORT MatSNESMFWPSetComputeNormU(Mat A,PetscTruth 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

-snes_mf_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 MATSNESMF_WP for a complete description of the algorithm used to compute h.

See Also

MatSNESMFSetFunctionError(), MatCreateSNESMF()

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