com.barrybecker4.optimization.optimizee.optimizees.OptimizeeProblem Maven / Gradle / Ivy

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/** Copyright by Barry G. Becker, 2000-2013. Licensed under MIT License: http://www.opensource.org/licenses/MIT  */
package com.barrybecker4.optimization.optimizee.optimizees;

import com.barrybecker4.optimization.optimizee.Optimizee;
import com.barrybecker4.optimization.parameter.ParameterArray;

/**
 * Abstract base class for optimizer test problems.
 *
 * @author Barry Becker
 */
public abstract class OptimizeeProblem implements Optimizee {

    /** @return  the exact solution for this problem. */
    public abstract ParameterArray getExactSolution();

    /** @return  the exact solution for this problem. */
    public abstract ParameterArray getInitialGuess();

    /**
     * @param sol solution
     * @return distance from the exact solution as the error.
     */
    public double getError(ParameterArray sol) {
        return 100.0 * (sol.getFitness() - getOptimalFitness()) / getFitnessRange();
    }

    @Override
    public double getOptimalFitness() {
        return 0;
    }

    @Override
    public double compareFitness(ParameterArray a, ParameterArray b) {
        return 0.0;
    }

    @Override
    public String toString() {
        return getName();
    }

    /**
     *
     * @return  approximate range of fitness values (usually 0 to this number).
     */
    public abstract double getFitnessRange();


    public static void showSolution(OptimizeeProblem problem, ParameterArray solution) {
        System.out.println( "\n************************************************************************" );
        System.out.println( "The solution to the "+problem.getName() +" test problem is :\n" + solution );
        System.out.println( "Which evaluates to: " + problem.evaluateFitness(solution));
        System.out.println( "We expected to get exactly " + problem.getExactSolution());
    }
}