SNESNCG#

Nonlinear Conjugate-Gradient method for the solution of nonlinear systems.

Options Database Keys#

  • -snes_ncg_type <fr, prp, dy, hs, cd> - Choice of conjugate-gradient update parameter, default is prp.

  • -snes_linesearch_type <cp,l2,basic> - Line search type.

  • -snes_ncg_monitor - Print the beta values used in the ncg iteration, .

Notes#

This solves the nonlinear system of equations F(x) = 0 using the nonlinear generalization of the conjugate gradient method. This may be used with a nonlinear preconditioner used to pick the new search directions, but otherwise chooses the initial search direction as F(x) for the initial guess x.

Only supports left non-linear preconditioning.

Default line search is SNESLINESEARCHCP, unless a nonlinear preconditioner is used with -npc_snes_type , SNESSetNPC(), or SNESGetNPC() then SNESLINESEARCHL2 is used. Also supports the special purpose line search SNESLINESEARCHNCGLINEAR

References#

  • **** -*** Peter R. Brune, Matthew G. Knepley, Barry F. Smith, and Xuemin Tu,”Composing Scalable Nonlinear Algebraic Solvers”, SIAM Review, 57(4), 2015

See Also#

SNESCreate(), SNES, SNESSetType(), SNESNEWTONLS, SNESNEWTONTR, SNESNGMRES, SNESQN, SNESLINESEARCHNCGLINEAR, SNESNCGSetType(), SNESLineSearchSetType()

Level#

beginner

Location#

src/snes/impls/ncg/snesncg.c

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Index of all SNES routines
Table of Contents for all manual pages
Index of all manual pages