petsc-3.7.1 2016-05-15
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SNESKSPSetUseEW

Sets SNES use Eisenstat-Walker method for computing relative tolerance for linear solvers within an inexact Newton method.

Synopsis

#include "petscsnes.h"  
PetscErrorCode  SNESKSPSetUseEW(SNES snes,PetscBool flag)
Logically Collective on SNES Many br

Input Parameters

snes - SNES context Many br
flag - PETSC_TRUE or PETSC_FALSE Many br

Options Database

-snes_ksp_ew - use Eisenstat-Walker method for determining linear system convergence Many br
-snes_ksp_ew_version ver - version of Eisenstat-Walker method Many br
-snes_ksp_ew_rtol0 <rtol0> - Sets rtol0 Many br
-snes_ksp_ew_rtolmax <rtolmax> - Sets rtolmax Many br
-snes_ksp_ew_gamma <gamma> - Sets gamma Many br
-snes_ksp_ew_alpha <alpha> - Sets alpha Many br
-snes_ksp_ew_alpha2 <alpha2> - Sets alpha2 Many br
-snes_ksp_ew_threshold <threshold> - Sets threshold Many br

Notes

Currently, the default is to use a constant relative tolerance for Many brthe inner linear solvers. Alternatively, one can use the Many brEisenstat-Walker method, where the relative convergence tolerance Many bris reset at each Newton iteration according progress of the nonlinear Many brsolver. Many br

Many br

Reference

S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in an Many brinexact Newton method", SISC 17 (1), pp.16-32, 1996. Many br

Keywords

SNES, KSP, Eisenstat, Walker, convergence, test, inexact, Newton

See Also

SNESKSPGetUseEW(), SNESKSPGetParametersEW(), SNESKSPSetParametersEW()

Level:advanced
Location:
src/snes/interface/snes.c
Index of all SNES routines
Table of Contents for all manual pages
Index of all manual pages