SNESLineSearchSetDamping#
Sets the line search damping parameter.
Synopsis#
#include "petscsnes.h"
PetscErrorCode SNESLineSearchSetDamping(SNESLineSearch linesearch, PetscReal damping)
Input Parameters#
linesearch - the line search context
damping - The damping parameter
Options Database Key#
-snes_linesearch_damping
- the damping value
Note#
The SNESLINESEARCHNONE line search merely takes the update step scaled by the damping parameter.
The use of the damping parameter in the SNESLINESEARCHSECANT and SNESLINESEARCHCP line searches is much more subtle;
it is used as a starting point for the secant method. Depending on the choice for maxlambda,
the eventual lambda may be greater than the damping parameter however.
For SNESLINESEARCHBISECTION and SNESLINESEARCHBT the damping is instead used as the initial guess,
below which the line search will not go. Hence, it is the maximum possible value for lambda.
See Also#
SNES: Nonlinear Solvers, SNES, SNESLineSearch, SNESLineSearchGetDamping()
Level#
intermediate
Location#
src/snes/linesearch/interface/linesearch.c
Index of all SNES routines
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Index of all manual pages