petsc-3.4.5 2014-06-29

SNESLINESEARCHBT

 Backtracking line search. This line search finds the minimum of a polynomial fitting of the L2 norm of the function. If this fit does not satisfy the conditions for progress, the interval shrinks and the fit is reattempted at most max_it times or until lambda is below minlambda.

Options Database Keys

-snes_linesearch_alpha<1e- 4> - slope descent parameter
-snes_linesearch_damping<1.0> - initial step length
-snes_linesearch_max_it<40> - maximum number of shrinking step
-snes_linesearch_minlambda<1e- 12> - minimum step length allowed
-snes_linesearch_order<cubic,quadratic> - order of the approximation

Notes

This line search is taken from "Numerical Methods for Unconstrained Optimization and Nonlinear Equations" by Dennis and Schnabel, page 325.

Keywords

SNES, SNESLineSearch, damping

See Also

SNESLineSearchCreate(), SNESLineSearchSetType()

Level:advanced
Location:src/snes/linesearch/impls/bt/linesearchbt.c
Index of all SNES routines
Table of Contents for all manual pages
Index of all manual pages