com.xj.anylogic.engine
Class OptimizationCallback

java.lang.Object
  com.xj.anylogic.engine.OptimizationCallback

public abstract class OptimizationCallback
extends java.lang.Object

This class is designed for usage in optimizations performed within custom experiments, see ExperimentOptimization.createOptimization(Engine, OptimizationCallback).

Usage example (the code of custom experiment, requires import com.opttek.optquest.*;):

 try {
        // Create Engine, initialize random number generator:
        Engine engine = createEngine();
        // Set stop time:
        engine.setStopTime(1);
 
        // Create optimization variable
        final COptQuestContinuousVariable v = new COptQuestContinuousVariable();
        v.SetLowerBound(0.0);
        v.SetUpperBound(100.0);
 
        // Create objective
        final COptQuestObjective obj = new COptQuestUserControlledObjective();
        obj.SetMinimize();
 
        // Create optimization engine
        final COptQuestOptimization opt = ExperimentOptimization.createOptimization(engine, new OptimizationCallback() {
 
                                @Override
                                public void evaluate(COptQuestOptimization optimization,
                                                COptQuestSolution solution, Engine engine) {
                                        try {
                                                // Create new root object:
                                                Main root = new Main(engine, null, null);
                                                // Setup parameters of root object here
                                                root.param = solution.GetVariableValue(v);
                                                // Prepare Engine for simulation:
                                                engine.start(root);
                                                // Start simulation in fast mode:
                                                engine.runFast();
                                                // Process results of simulation here
                                                solution.SetObjectiveValue(obj, root.objective);
                                                // Destroy the model:
                                                engine.stop();
                                        } catch (COptQuestException e) {
                                                traceln(e.Description());
                                        }
                                }
 
                                // Trace each iteration (optional!)
                                @Override
                                public void monitorStatus(COptQuestOptimization optimization,
                                                COptQuestSolution solution, Engine engine) {
                                        try {
                                                traceln(String.format(
                                                                "  %3d : %6.2f : %8.2f  -- %8.2f",
                                                                solution.GetIteration(),
                                                                solution.GetVariableValue(v),
                                                                solution.GetObjectiveValue(),
                                                                optimization.GetBestSolution() != null ? optimization
                                                                                .GetBestSolution().GetObjectiveValue(
                                                                                                obj) : Double.NaN));
                                        } catch (COptQuestException e) {
                                                traceln(e.Description());
                                        }
                                }
 
                        });
 
        // Setup optimization engine
        opt.AddVariable(v);
        opt.AddObjective(obj);
        // Set the number of iterations to run
        opt.SetMaximumIterations(500);
 
  // Add suggested solution (initial solution)
        COptQuestSolution suggestedSolution = opt.CreateSolution();
        suggestedSolution.SetVariableValue(v, 50.0);
        opt.AddSuggestedSolution(suggestedSolution);
 
        // Perform optimization
        opt.Optimize();
 
        // Output results
        COptQuestSolution bestSolution = opt.GetBestSolution();
        traceln("Best objective: " + format(bestSolution.GetObjectiveValue(obj)));
        traceln("Best parameter: " + format(bestSolution.GetVariableValue(v)));
 } catch (COptQuestException e) {
        traceln(e.Description());
 }
 

Author:

XJ Technologies Company Ltd. www.anylogic.com

See Also:

ExperimentOptimization.createOptimization(Engine, OptimizationCallback)

Constructor Summary

OptimizationCallback()

Method Summary

abstract void	evaluate(com.opttek.optquest.COptQuestOptimization optimization, com.opttek.optquest.COptQuestSolution solution, Engine engine) This callback should evaluate a solution.
void	monitorStatus(com.opttek.optquest.COptQuestOptimization optimization, com.opttek.optquest.COptQuestSolution solution, Engine engine) This method is called at the end of each iteration (after evaluate(COptQuestOptimization, COptQuestSolution, Engine)).

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

OptimizationCallback

public OptimizationCallback()

Method Detail

evaluate

public abstract void evaluate(com.opttek.optquest.COptQuestOptimization optimization,
                              com.opttek.optquest.COptQuestSolution solution,
                              Engine engine)

This callback should evaluate a solution.
This method is called at each iteration/replication of optimization.
Please call COptQuestVariable.GetCurrentValue() to obtain calculated values of optimization parameters and save objective value using COptQuestOptimization.SetCurrentObjectiveValue(double)
The most common implementation of this method is a single simulation (using runFast()) of a newly created (each time) model active object

Parameters:

optimization - optimization engine instance

solution - solution being evaluated

engine - AnyLogic engine instance

monitorStatus

public void monitorStatus(com.opttek.optquest.COptQuestOptimization optimization,
                          com.opttek.optquest.COptQuestSolution solution,
                          Engine engine)

This method is called at the end of each iteration (after evaluate(COptQuestOptimization, COptQuestSolution, Engine)).
When this method is called, the solution has been checked for feasibility.

Parameters:

optimization - optimization engine instance

solution - the solution

engine - AnyLogic engine instance