petsc-3.14.5 2021-03-03
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# TaoLineSearchGetSolution

Returns the solution to the line search

### Synopsis

    #include "petsctaolinesearch.h"
    PetscErrorCode TaoLineSearchGetSolution(TaoLineSearch ls, Vec x, PetscReal *f, Vec g, PetscReal *steplength, TaoLineSearchConvergedReason *reason)

Collective on TaoLineSearch

### Input Parameter

| ls | - the TaoLineSearch context

### Output Parameter

| x | - the new solution
| f | - the objective function value at x
| g | - the gradient at x
| steplength | - the multiple of the step direction taken by the line search
| reason | - the reason why the line search terminated

### reason will be set to one of

| TAOLINESEARCH_FAILED_INFORNAN | - function evaluation gives Inf or Nan value
| TAOLINESEARCH_FAILED_BADPARAMETER | - negative value set as parameter
| TAOLINESEARCH_FAILED_ASCENT | - initial line search step * g is not descent direction
| TAOLINESEARCH_HALTED_MAXFCN | - maximum number of function evaluation reached
| TAOLINESEARCH_HALTED_UPPERBOUND | - step is at upper bound
| TAOLINESEARCH_HALTED_LOWERBOUND | - step is at lower bound
| TAOLINESEARCH_HALTED_RTOL | - range of uncertainty is smaller than given tolerance

| TAOLINESEARCH_HALTED_USER | - user can set this reason to stop line search
| TAOLINESEARCH_HALTED_OTHER | - any other reason

| TAOLINESEARCH_SUCCESS | - successful line search

### Level

developer

### Location

src/tao/linesearch/interface/taolinesearch.c
Index of all TaoLineSearch routines
Table of Contents for all manual pages
Index of all manual pages