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jMetal problem classes, including single- and multi-objective benchmarks
// Shapes.java
//
// Author:
// Antonio J. Nebro
// Juan J. Durillo
//
// Copyright (c) 2011 Antonio J. Nebro, Juan J. Durillo
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this program. If not, see .
package org.uma.jmetal.problem.multiobjective.wfg;
/**
* Class implementing shape functions for wfg benchmark
* Reference: Simon Huband, Luigi Barone, Lyndon While, Phil Hingston
* A Scalable Multi-objective Test Problem Toolkit.
* Evolutionary Multi-Criterion Optimization:
* Third International Conference, EMO 2005.
* Proceedings, volume 3410 of Lecture Notes in Computer Science
*/
public class Shapes {
/**
* Calculate a linear shape
*/
public float linear(float[] x, int m) {
float result = (float) 1.0;
int M = x.length;
for (int i = 1; i <= M - m; i++) {
result *= x[i - 1];
}
if (m != 1) {
result *= (1 - x[M - m]);
}
return result;
}
/**
* Calculate a convex shape
*/
public float convex(float[] x, int m) {
float result = (float) 1.0;
int M = x.length;
for (int i = 1; i <= M - m; i++) {
result *= (1 - Math.cos(x[i - 1] * Math.PI * 0.5));
}
if (m != 1) {
result *= (1 - Math.sin(x[M - m] * Math.PI * 0.5));
}
return result;
}
/**
* Calculate a concave shape
*/
public float concave(float[] x, int m) {
float result = (float) 1.0;
int M = x.length;
for (int i = 1; i <= M - m; i++) {
result *= Math.sin(x[i - 1] * Math.PI * 0.5);
}
if (m != 1) {
result *= Math.cos(x[M - m] * Math.PI * 0.5);
}
return result;
}
/**
* Calculate a mixed shape
*/
public float mixed(float[] x, int A, float alpha) {
float tmp;
tmp =
(float) Math.cos((float) 2.0 * A * (float) Math.PI * x[0] + (float) Math.PI * (float) 0.5);
tmp /= (2.0 * (float) A * Math.PI);
return (float) Math.pow(((float) 1.0 - x[0] - tmp), alpha);
}
/**
* Calculate a disc shape
*/
public float disc(float[] x, int A, float alpha, float beta) {
float tmp;
tmp = (float) Math.cos((float) A * Math.pow(x[0], beta) * Math.PI);
return (float) 1.0 - (float) Math.pow(x[0], alpha) * (float) Math.pow(tmp, 2.0);
}
}