TaoGetObjectiveAndGradient#

Gets the combined objective function and gradient evaluation routine for the function to be optimized

Synopsis#

#include "petsctao.h" 
PetscErrorCode TaoGetObjectiveAndGradient(Tao tao, Vec *g, PetscErrorCode (**func)(Tao tao, Vec x, PetscReal *f, Vec g, PetscCtx ctx), PetscCtxRt ctx)

Not Collective

Input Parameter#

tao - the Tao context

Output Parameters#

g - the vector to internally hold the gradient computation
func - the gradient function
ctx - user-defined context for private data for the gradient evaluation routine

Calling sequence of `func`#

tao - the optimizer
x - input vector
f - objective value (output)
g - gradient value (output)
ctx - [optional] user-defined function context

Note#

In addition to specifying an objective function using callbacks such as TaoSetObjectiveAndGradient(), users can specify objective functions with TaoAddTerm().

TaoGetObjectiveAndGradient() will always return the callback specified with TaoSetObjectiveAndGradient(), even if the objective function has been changed by calling TaoAddTerm().

Level#

beginner

Location#

src/tao/interface/taosolver_fg.c

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