TaoLineSearchSetGradientRoutine#

Sets the gradient evaluation routine for the line search

Synopsis#

#include "petsctaolinesearch.h" 
PetscErrorCode TaoLineSearchSetGradientRoutine(TaoLineSearch ls, PetscErrorCode (*func)(TaoLineSearch ls, Vec x, Vec g, void *), void *ctx)

Logically Collective

Input Parameters#

ls - the TaoLineSearch context
func - the gradient evaluation routine
ctx - the (optional) user-defined context for private data

Calling sequence of `func`#

PetscErrorCode func(TaoLinesearch ls, Vec x, Vec g, void *ctx);

ls - the linesearch object
x - input vector
g - gradient vector
ctx (optional) user- defined context

Note#

Use this routine only if you want the line search gradient evaluation routine to be different from the Tao’s gradient evaluation routine. If you use this routine you must also set the line search function and/or function/gradient routine.

Some algorithms (lcl, gpcg) set their own gradient routine for the line search, application programmers should be wary of overriding the default gradient routine.