petsc-3.10.5 2019-03-28
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# SNESLINESEARCHCP

Critical point line search. This line search assumes that there exists some artificial G(x) for which the SNESFunction F(x) = grad G(x). Therefore, this line search seeks to find roots of dot(F, Y) via a secant method.

### Options Database Keys

| -snes_linesearch_minlambda <minlambda> | - the minimum acceptable lambda
| -snes_linesearch_maxstep <length> | - the algorithm insures that a step length is never longer than this value
| -snes_linesearch_damping <damping> | - initial trial step length is scaled by this factor, default is 1.0
| -snes_linesearch_max_it <max_it> | - the maximum number of secant steps performed.

### Notes

This method does NOT use the objective function if it is provided with SNESSetObjective().

This method is the preferred line search for SNESQN and SNESNCG.

### Keywords

SNES, SNESLineSearch, damping

### See Also

SNESLineSearchCreate(), SNESLineSearchSetType()

### Level

advanced

### Location

src/snes/linesearch/impls/cp/linesearchcp.c
Index of all SNES routines
Table of Contents for all manual pages
Index of all manual pages