petsc-3.7.1 2016-05-15
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# SNESNRICHARDSON

Richardson nonlinear solver that uses successive substitutions, also sometimes known as Picard iteration. Many br

### Options Database

| -snes_linesearch_type <l2,cp,basic> Line search type. | - - -snes_linesearch_damping<1.0> Damping for the line search. Many br

Notes: If no inner nonlinear preconditioner is provided then solves F(x) - b = 0 using x^{n+1} = x^{n} - lambda Many br(F(x^n) - b) where lambda is obtained either SNESLineSearchSetDamping(), -snes_damping or a line search. If Many bran inner nonlinear preconditioner is provided (either with -npc_snes_type or SNESSetNPC()) then the inner Many brsolver is called an initial solution x^n and the nonlinear Richardson uses x^{n+1} = x^{n} + lambda d^{n} Many brwhere d^{n} = \hat{x}^{n} - x^{n} where \hat{x}^{n} is the solution returned from the inner solver. Many br

The update, especially without inner nonlinear preconditioner, may be ill-scaled. If using the basic Many brlinesearch, one may have to scale the update with -snes_linesearch_damping Many br

This uses no derivative information thus will be much slower then Newton's method obtained with -snes_type ls Many br

### See Also

SNESCreate(), SNES, SNESSetType(), SNESNEWTONLS, SNESNEWTONTR, SNESNGMRES, SNESQN, SNESNCG

Level:beginner
Location:src/snes/impls/richardson/snesrichardson.c
Index of all SNES routines
Table of Contents for all manual pages
Index of all manual pages