org.jamesframework.ext.problems.objectives

Class NormalizedObjective<SolutionType extends org.jamesframework.core.problems.sol.Solution,DataType>

java.lang.Object

org.jamesframework.ext.problems.objectives.NormalizedObjective<SolutionType,DataType>

Type Parameters:

SolutionType - solution type to be evaluated, required to extend Solution

DataType - underlying data type

All Implemented Interfaces:

org.jamesframework.core.problems.objectives.Objective<SolutionType,DataType>

public class NormalizedObjective<SolutionType extends org.jamesframework.core.problems.sol.Solution,DataType>
extends Object
implements org.jamesframework.core.problems.objectives.Objective<SolutionType,DataType>

A normalized objective wraps another objective and normalizes all produces evaluations from a given interval [min, max] to [0, 1]. Normalization is linear, using the formula \[ normalized = \frac{value - min}{max - min}. \] Both methods used for full and delta evaluation return a NormalizedEvaluation.

Author:

Herman De Beukelaer

Constructor Summary

Constructors

Constructor and Description
NormalizedObjective(org.jamesframework.core.problems.objectives.Objective<? super SolutionType,? super DataType> obj, double min, double max) Create a normalized objective that wraps the given objective and normalizes all produced evaluation from [min, max] to [0, 1].

Method Summary

Modifier and Type	Method and Description
<ActualSolutionType extends SolutionType> NormalizedEvaluation	evaluate(org.jamesframework.core.search.neigh.Move<? super ActualSolutionType> move, ActualSolutionType curSolution, org.jamesframework.core.problems.objectives.evaluations.Evaluation curEvaluation, DataType data) Computes the normalized evaluation of the solution obtained by applying the given move to the current solution.
NormalizedEvaluation	evaluate(SolutionType solution, DataType data) Computes the normalized evaluation of the given solution.
double	getMax() Get upper bound of normalization interval
double	getMin() Get lower bound of normalization interval.
org.jamesframework.core.problems.objectives.Objective<? super SolutionType,? super DataType>	getUnnormalizedObjective() Get the original, unnormalized objective.
boolean	isMinimizing() Indicates whether the produced evaluations are to be minimized.
String	toString() Create string representation of normalized objective, indicating the original, unnormalized objective and normalization interval.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

NormalizedObjective

public NormalizedObjective(org.jamesframework.core.problems.objectives.Objective<? super SolutionType,? super DataType> obj,
                           double min,
                           double max)

Create a normalized objective that wraps the given objective and normalizes all produced evaluation from [min, max] to [0, 1].

Parameters:

obj - original, unnormalized objective

min - lower bound of normalization interval

max - upper bound of normalization interval

Throws:

NullPointerException - if obj is null

Method Detail

getUnnormalizedObjective

public org.jamesframework.core.problems.objectives.Objective<? super SolutionType,? super DataType> getUnnormalizedObjective()

Get the original, unnormalized objective.

Returns:

unnormalized objective

getMin

public double getMin()

Get lower bound of normalization interval.

Returns:

lower bound

getMax

public double getMax()

Get upper bound of normalization interval

Returns:

upper bound

evaluate

public NormalizedEvaluation evaluate(SolutionType solution,
                                     DataType data)

Computes the normalized evaluation of the given solution. The solution is first evaluated using the original, unnormalized objective after which the returned evaluation is wrapped in a NormalizedEvaluation.

Specified by:

evaluate in interface org.jamesframework.core.problems.objectives.Objective<SolutionType extends org.jamesframework.core.problems.sol.Solution,DataType>

Parameters:

solution - solution to evaluate

data - underlying data

Returns:

normalized evaluation

evaluate

public <ActualSolutionType extends SolutionType> NormalizedEvaluation evaluate(org.jamesframework.core.search.neigh.Move<? super ActualSolutionType> move,
                                                                               ActualSolutionType curSolution,
                                                                               org.jamesframework.core.problems.objectives.evaluations.Evaluation curEvaluation,
                                                                               DataType data)

Computes the normalized evaluation of the solution obtained by applying the given move to the current solution. Relies on delta evaluation performed by the original, unnormalized objective, whose result is wrapped in a NormalizedEvaluation.

Specified by:

evaluate in interface org.jamesframework.core.problems.objectives.Objective<SolutionType extends org.jamesframework.core.problems.sol.Solution,DataType>

Type Parameters:

ActualSolutionType - the actual solution type of the problem that is being solved; a subtype of the solution types of both the objective and the applied move

Parameters:

move - move to evaluate

curSolution - current solution

curEvaluation - evaluation of current solution

data - underlying data used for evaluation

Returns:

evaluation of modified solution obtained when applying the move to the current solution

Throws:

org.jamesframework.core.exceptions.IncompatibleDeltaEvaluationException - if the delta evaluation of the original objective is not compatible with the received move type

isMinimizing

public boolean isMinimizing()

Indicates whether the produced evaluations are to be minimized. Delegates to the original, unnormalized evaluation.

Specified by:

isMinimizing in interface org.jamesframework.core.problems.objectives.Objective<SolutionType extends org.jamesframework.core.problems.sol.Solution,DataType>

Returns:

true if evaluations are to be minimized, false if they are to be maximized

toString

public String toString()

Create string representation of normalized objective, indicating the original, unnormalized objective and normalization interval.

Overrides:

toString in class Object

Returns:

string representation