SNES_KSP_SetParametersEW

Sets parameters for Eisenstat-Walker convergence criteria for the linear solvers within an inexact Newton method.

Synopsis

int SNES_KSP_SetParametersEW(SNES snes,int version,double rtol_0,
                             double rtol_max,double gamma2,double alpha,
                             double alpha2,double threshold)
Collective on SNES

Input Parameters

snes - SNES context
version - version 1 or 2 (default is 2)
rtol_0 - initial relative tolerance (0 <= rtol_0 < 1)
rtol_max - maximum relative tolerance (0 <= rtol_max < 1)
alpha - power for version 2 rtol computation (1 < alpha <= 2)
alpha2 - power for safeguard
gamma2 - multiplicative factor for version 2 rtol computation (0 <= gamma2 <= 1)
threshold - threshold for imposing safeguard (0 < threshold < 1)

Note

Use PETSC_DEFAULT to retain the default for any of the parameters.

Reference

S. C. Eisenstat and H. F. Walker, "Choosing the forcing terms in aninexact Newton method", Utah State University Math. Stat. Dept. Res. Report 6/94/75, June, 1994, to appear in SIAM J. Sci. Comput.

Keywords

SNES, KSP, Eisenstat, Walker, set, parameters

See Also

SNES_KSP_SetConvergenceTestEW()

Location: src/snes/interface/snesut.c
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