/*
* Copyright (c) 2012, Søren Atmakuri Davidsen
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package fuzzy4j.sets;
import fuzzy4j.util.SimpleInterval;
/**
* Defines simple apply functions for use in every-day fuzzy logic problems :-)
*
* @author Soren AD <sdavid08@student.aau.dk>
*/
public class SetsFactory {
private static class SplitFunction implements FuzzyFunction {
private double a;
private FuzzyFunction lte;
private FuzzyFunction gt;
public SplitFunction(double a, FuzzyFunction lte, FuzzyFunction gt) {
this.a = a;
this.lte = lte;
this.gt = gt;
}
@Override
public double apply(double x) {
if (x <= a)
return lte.apply(x);
else
return gt.apply(x);
}
}
private static class DifferenceFunction implements FuzzyFunction {
private FuzzyFunction f1, f2;
private DifferenceFunction(FuzzyFunction f1, FuzzyFunction f2) {
this.f1 = f1;
this.f2 = f2;
}
@Override
public double apply(double x) {
return Math.max(0.0, f1.apply(x) - f2.apply(x));
}
}
private static class SumFunction implements FuzzyFunction {
private FuzzyFunction f1, f2;
private SumFunction(FuzzyFunction f1, FuzzyFunction f2) {
this.f1 = f1;
this.f2 = f2;
}
@Override
public double apply(double x) {
return Math.min(1.0, f1.apply(x) + f2.apply(x));
}
}
private static class Pow2Function implements FuzzyFunction, SupportAware {
private double a;
private double n;
public Pow2Function(double a) {
this.a = a;
this.n = Math.pow(a, 2);
}
@Override
public double apply(double x) {
if (x <= 0)
return 0.0;
if (x >= a)
return 1.0;
else
return Math.pow(x, 2) / n;
}
@Override
public SimpleInterval support() {
return new SimpleInterval(false, 0.0, Double.POSITIVE_INFINITY, true);
}
}
private static class PowerFunction implements FuzzyFunction, SupportAware {
private double b;
private double a;
public PowerFunction(double b, double a) {
this.b = b;
this.a = a;
}
@Override
public double apply(double x) {
return b * Math.pow(x, a);
}
@Override
public SimpleInterval support() {
return new SimpleInterval(false, 0.0, Double.POSITIVE_INFINITY, true);
}
public String toString() {
return String.format("%f x^%f", b, a);
}
}
private static class ExpFunction implements FuzzyFunction {
private double b;
private double a;
public ExpFunction(double a, double b) {
this.b = b;
this.a = a;
}
@Override
public double apply(double x) {
return b * Math.exp(x * a);
}
public String toString() {
return String.format("%f^%fx", b, a);
}
}
private static class Log10Function implements FuzzyFunction {
private double a;
public Log10Function(double a) {
this.a = a;
}
@Override
public double apply(double x) {
return Math.log10(x);
}
}
}