petsc-3.7.1 2016-05-15

SNESLineSearchApply

Computes the line-search update.

Synopsis

#include "petscsnes.h" 
PetscErrorCode SNESLineSearchApply(SNESLineSearch linesearch, Vec X, Vec F, PetscReal * fnorm, Vec Y)

Collective on SNESLineSearch Many br

Input Parameters

	linesearch	- The linesearch context Many br
	X	- The current solution Many br
	F	- The current function Many br
	fnorm	- The current norm Many br
	Y	- The search direction Many br

Output Parameters

	X	- The new solution Many br
	F	- The new function Many br
	fnorm	- The new function norm Many br

Options Database Keys

	-snes_linesearch_type	- basic, bt, l2, cp, nleqerr, shell Many br
	-snes_linesearch_monitor [:filename]	- Print progress of line searches Many br
	-snes_linesearch_damping	- The linesearch damping parameter Many br
	-snes_linesearch_norms	- Turn on/off the linesearch norms Many br
	-snes_linesearch_keeplambda	- Keep the previous search length as the initial guess Many br
	-snes_linesearch_max_it	- The number of iterations for iterative line searches Many br

Notes

This is typically called from within a SNESSolve() implementation in order to Many brhelp with convergence of the nonlinear method. Various SNES types use line searches Many brin different ways, but the overarching theme is that a line search is used to determine Many bran optimal damping parameter of a step at each iteration of the method. Each Many brapplication of the line search may invoke SNESComputeFunction several times, and Many brtherefore may be fairly expensive. Many br

Many br

Keywords

SNESLineSearch, Create