petsc-3.14.6 2021-03-30

SNESLINESEARCHBASIC

This line search implementation is not a line search at all; it simply uses the full step. Thus, this routine is intended for methods with well-scaled updates; i.e. Newton's method (SNESNEWTONLS), on well-behaved problems.

Options Database Keys

	-snes_linesearch_damping <damping>	- search vector is scaled by this amount, default is 1.0
	-snes_linesearch_norms <flag>	- whether to compute norms or not, default is true (SNESLineSearchSetComputeNorms())

Notes

For methods with ill-scaled updates (SNESNRICHARDSON, SNESNCG), a small damping parameter may yield satisfactory but slow convergence despite the simplicity of the line search.

Level

advanced

Location

src/snes/linesearch/impls/basic/linesearchbasic.c

Examples