petsc-3.10.5 2019-03-28
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# SNESLineSearchSetFromOptions

Sets options for the line search

### Synopsis

    #include "petscsnes.h"
    PetscErrorCode SNESLineSearchSetFromOptions(SNESLineSearch linesearch)

### Input Parameters

linesearch -linesearch context

### Options Database Keys

| -snes_linesearch_type <type> | - basic, bt, l2, cp, nleqerr, shell
| -snes_linesearch_order <order> | - 1, 2, 3. Most types only support certain orders (bt supports 2 or 3)
| -snes_linesearch_norms | - Turn on/off the linesearch norms for the basic linesearch typem (SNESLineSearchSetComputeNorms())
| -snes_linesearch_minlambda | - The minimum step length
| -snes_linesearch_maxstep | - The maximum step size
| -snes_linesearch_rtol | - Relative tolerance for iterative line searches
| -snes_linesearch_atol | - Absolute tolerance for iterative line searches
| -snes_linesearch_ltol | - Change in lambda tolerance for iterative line searches
| -snes_linesearch_max_it | - The number of iterations for iterative line searches
| -snes_linesearch_monitor [:filename] | - Print progress of line searches
| -snes_linesearch_monitor_solution_update [viewer:filename:format] | - view each update tried by line search routine
| -snes_linesearch_damping | - The linesearch damping parameter
| -snes_linesearch_keeplambda | - Keep the previous search length as the initial guess.
| -snes_linesearch_precheck_picard | - Use precheck that speeds up convergence of picard method
| -snes_linesearch_precheck_picard_angle | - Angle used in picard precheck method

Logically Collective on SNESLineSearch

### See Also

SNESLineSearchCreate(), SNESLineSearchSetOrder(), SNESLineSearchSetType(), SNESLineSearchSetTolerances(), SNESLineSearchSetDamping(), SNESLineSearchPreCheckPicard(),
SNESLineSearchType, SNESLineSearchSetComputeNorms()

### Level

intermediate

### Location

src/snes/linesearch/interface/linesearch.c

### Implementations

SNESLineSearchSetFromOptions_BT in src/snes/linesearch/impls/bt/linesearchbt.c
Index of all SNES routines
Table of Contents for all manual pages
Index of all manual pages