SNESQNSetScaleType

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

Synopsis

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

Logically Collective

Input Parameters

• snes - the nonlinear solver context

• stype - scale type

Options Database Key

• -snes_qn_scale_type <diagonal,none,scalar,jacobian> - Scaling type

SNESQNScaleTypes

• SNES_QN_SCALE_NONE - don’t scale the problem

• SNES_QN_SCALE_SCALAR - use Shanno scaling

• SNES_QN_SCALE_DIAGONAL - scale with a diagonalized BFGS formula (see Gilbert and Lemarechal 1989), available

• 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.

See Also

SNES, SNESQN, SNESLineSearch, SNESQNScaleType, SNESSetJacobian()

Level

intermediate

Location

src/snes/impls/qn/qn.c

Implementations

SNESQNSetScaleType_QN in src/snes/impls/qn/qn.c

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