petsc-3.12.5 2020-03-29
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SNESNCGSetType

Sets the conjugate update type for SNESNCG.

Synopsis

#include "petscsnes.h" 
PetscErrorCode SNESNCGSetType(SNES snes, SNESNCGType btype)
Logically Collective on SNES

Input Parameters

snes - the iterative context
btype - update type

Options Database

-snes_ncg_type <prp,fr,hs,dy,cd> -strategy for selecting algorithm for computing beta

SNESNCGSelectTypes

SNES_NCG_FR - Fletcher-Reeves update
SNES_NCG_PRP - Polak-Ribiere-Polyak update
SNES_NCG_HS - Hestenes-Steifel update
SNES_NCG_DY - Dai-Yuan update
SNES_NCG_CD - Conjugate Descent update

Notes

SNES_NCG_PRP is the default, and the only one that tolerates generalized search directions.

It is not clear what "generalized search directions" means, does it mean use with a nonlinear preconditioner, that is using -npc_snes_type <type>, SNESSetNPC(), or SNESGetNPC()?

Level

intermediate

Location

src/snes/impls/ncg/snesncg.c

Implementations

SNESNCGSetType_NCG in src/snes/impls/ncg/snesncg.c

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