petsc-3.8.4 2018-03-24
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SNESQNSetScaleType

 Sets the scaling type for the inner inverse Jacobian in SNESQN.

Synopsis

#include "petscsnes.h" 
PetscErrorCode SNESQNSetScaleType(SNES snes, SNESQNScaleType stype)
Logically Collective on SNES

Input Parameters

snes - the iterative context
stype - scale type

Options Database

-snes_qn_scale_type <shanno,none,linesearch,jacobian> -

SNESQNScaleTypes

SNES_QN_SCALE_NONE - don't scale the problem
SNES_QN_SCALE_SHANNO - use shanno scaling
SNES_QN_SCALE_LINESEARCH - scale based upon line search lambda
SNES_QN_SCALE_JACOBIAN - scale by solving a linear system coming from the Jacobian you provided with SNESSetJacobian() computed at the first iteration of QN and at ever restart.

Keywords

scaling type

See Also

SNES, SNESQN, SNESLineSearch, SNESQNScaleType, SNESetJacobian()

Level:intermediate
Location:src/snes/impls/qn/qn.c
Index of all SNES routines
Table of Contents for all manual pages
Index of all manual pages