chrono::ChOptimizerGradient Class Reference


Class for local optimization with the cheap method of gradient and bisection.

#include <ChSolvmin.h>

Inheritance diagram for chrono::ChOptimizerGradient:
Collaboration diagram for chrono::ChOptimizerGradient:

Public Member Functions

 ChOptimizerGradient (const ChOptimizerGradient &other)
virtual bool DoOptimize () override
 This function computes the optimal xv[]. More...
- Public Member Functions inherited from chrono::ChOptimizer
 ChOptimizer (const ChOptimizer &other)
virtual void SetObjective (ChFx *mformula)
 Sets the objective function to maximize.
virtual ChFxGetObjective () const
virtual void SetObjectiveGrad (ChFx *mformula)
 Sets the objective function gradient (not mandatory, because if not set, the default bacward differentiation is used).
virtual ChFxGetObjectiveGrad () const
virtual void SetNumOfVars (int mv)
 Set the number of optimization variables. More...
virtual int GetNumOfVars () const
 Returns the number of optimization variables.
double * GetXv () const
double * GetXv_sup () const
double * GetXv_inf () const
void SetXv (double *mx)
void SetXv_sup (double *mx)
void SetXv_inf (double *mx)
double Eval_fx (double x[])
 Returns the value of the functional, for given state of variables and with the given "database" multibody system. More...
double Eval_fx (const ChVectorDynamic<> &x)
void Eval_grad (double x[], double gr[])
 Computes the gradient of objective function, for given state of variables. More...
void Eval_grad (const ChVectorDynamic<> &x, ChVectorDynamic<> &gr)
virtual bool PreOptimize ()
 Performs the optimization of the ChSystem pointed by "database" (or whatever object which can evaluate the string "function" and the "optvarlist") using the current parameters. More...
virtual bool PostOptimize ()
 Finalization and cleanup.
virtual bool Optimize ()
 Does the three steps in sequence PreOptimize, DoOptimize, PostOptimize. More...
void DoBreakCheck ()
 Each break_cycles number of times this fx is called, the function break_funct() is evaluated (if any) and if positive, the variable user_break becomes true.

Public Attributes

double initial_step
 def = 1; initial trial step size
double arg_tol
 argument rel.error, def 1.e-6
double fun_tol
 function rel error, def 1.e-7
int maxevaluations
 max number of fx evaluations, def 800;
int maxgradients
 max number of gradient evaluations, def 50;
int maxdilationsteps
 max number of 'exploring' steps in forward gradient direction (def 8);
int maxbisections
 number of bisections in climbing interval, before recomputing gradient (def 10);
double dilation
 space dilation coeff, def. 2
bool do_conjugate
 if true, corrects the gradient by conjugate method (default= off)
- Public Attributes inherited from chrono::ChOptimizer
bool minimize
 default = false; just maximize
double grad_step
 default = 1.e-12; step size for evaluation of gradient
double opt_fx
 best resulting value of objective function
char err_message [200]
 the ok/warning/error messages are written here
int error_code
long fx_evaluations
 number of function evaluations
long grad_evaluations
 number of gradient evaluations
int(* break_funct )()
 if not null, this function is called each 'break_cycles' evaluations
int break_cycles
 how many fx evaluations per check
int user_break
 if break_funct() reported true, this flag is ON, and optimizers should exit all cycles
int break_cyclecounter

Additional Inherited Members

- Protected Attributes inherited from chrono::ChOptimizer
 the function to be maximized
 the gradient of the function to be maximized, or null for default BDF.
int C_vars
 number of input variables
double * xv
 Vector of variables, also 1st approximation.
double * xv_sup
 These are the hi/lo limits for the variables,.
double * xv_inf
 these are not used by all optimizer, and can be NULL for gradient, but needed for genetic.

Member Function Documentation

◆ DoOptimize()

bool chrono::ChOptimizerGradient::DoOptimize ( )

This function computes the optimal xv[].

It must be implemented by derived classes

Reimplemented from chrono::ChOptimizer.

The documentation for this class was generated from the following files:
  • /builds/uwsbel/chrono/src/chrono/solver/ChSolvmin.h
  • /builds/uwsbel/chrono/src/chrono/solver/ChSolvmin.cpp