SNESLINESEARCHNCGLINEAR

Special line search only for the nonlinear CG solver SNESNCG This line search uses the length “as if” the problem is linear (that is what is computed by the linear CG method) using the Jacobian of the function. alpha = (r, r) / (p, Ap) = (f, f) / (y, Jy) where r (f) is the current residual (function value), p (y) is the current search direction.

Notes

This requires a Jacobian-vector product but does not require the solution of a linear system with the Jacobian

This is a “odd-ball” line search, we don’t know if it is in the literature or used in practice by anyone.

See Also

SNES: Nonlinear Solvers, SNES, SNESNCG SNESLineSearchCreate(), SNESLineSearchSetType()

Level

advanced

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