// WFG1.java
//
// Author:
// Antonio J. Nebro <antonio@lcc.uma.es>
// Juan J. Durillo <durillo@lcc.uma.es>
//
// 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 <http://www.gnu.org/licenses/>.
package jmetal.problems.WFG;
import jmetal.core.Solution;
import jmetal.core.Variable;
import jmetal.util.JMException;
/**
* This class implements the WFG1 problem
* 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 WFG1 extends WFG {
/**
* Constructor
* Creates a default WFG1 instance with
* 2 position-related parameters
* 4 distance-related parameters
* and 2 objectives
* @param solutionType The solution type must "Real" or "BinaryReal".
*/
public WFG1(String solutionType) throws ClassNotFoundException {
this(solutionType, 2, 4, 2) ;
} // WFG1
/**
* Creates a WFG1 problem instance
* @param k Number of position parameters
* @param l Number of distance parameters
* @param M Number of objective functions
* @param solutionType The solution type must "Real" or "BinaryReal".
*/
public WFG1(String solutionType, Integer k, Integer l, Integer M) throws ClassNotFoundException {
super(solutionType, k,l,M);
problemName_ = "WFG1";
S_ = new int[M_];
for (int i = 0; i < M_; i++)
S_[i] = 2 * (i+1);
A_ = new int[M_-1];
for (int i = 0; i < M_-1; i++)
A_[i] = 1;
} // WFG1
/**
* Evaluates a solution
* @param z The solution to evaluate
* @return a double [] with the evaluation results
*/
public float [] evaluate(float [] z){
float [] y;
y = normalise(z);
y = t1(y,k_);
y = t2(y,k_);
try {
y = t3(y);
} catch (JMException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
y = t4(y,k_,M_);
float [] result = new float[M_];
float [] x = calculate_x(y);
for (int m = 1; m <= M_ - 1 ; m++) {
result [m-1] = D_*x[M_-1] + S_[m-1] * (new Shapes()).convex(x,m);
}
result[M_-1] = D_*x[M_-1] + S_[M_-1] * (new Shapes()).mixed(x,5,(float)1.0);
return result;
} // evaluate
/**
* WFG1 t1 transformation
*/
public float [] t1(float [] z, int k){
float [] result = new float[z.length];
System.arraycopy(z, 0, result, 0, k);
for (int i = k; i < z.length; i++) {
result[i] = (new Transformations()).s_linear(z[i],(float)0.35);
}
return result;
} // t1
/**
* WFG1 t2 transformation
*/
public float [] t2(float [] z, int k){
float [] result = new float[z.length];
System.arraycopy(z, 0, result, 0, k);
for (int i = k; i < z.length; i++) {
result[i] = (new Transformations()).b_flat(z[i],(float)0.8,(float)0.75,(float)0.85);
}
return result;
} // t2
/**
* WFG1 t3 transformation
* @throws JMException
*/
public float [] t3(float [] z) throws JMException{
float [] result = new float[z.length];
for (int i = 0; i < z.length; i++) {
result[i] = (new Transformations()).b_poly(z[i],(float)0.02);
}
return result;
} // t3
/**
* WFG1 t4 transformation
*/
public float [] t4(float [] z, int k, int M){
float [] result = new float[M];
float [] w = new float[z.length];
for (int i = 0; i < z.length; i++) {
w[i] = (float)2.0 * (i + 1);
}
for (int i = 1; i <= M-1; i++){
int head = (i - 1)*k/(M-1) + 1;
int tail = i * k / (M - 1);
float [] subZ = subVector(z,head-1,tail-1);
float [] subW = subVector(w,head-1,tail-1);
result[i-1] = (new Transformations()).r_sum(subZ,subW);
}
int head = k + 1 - 1;
int tail = z.length - 1;
float [] subZ = subVector(z,head,tail);
float [] subW = subVector(w,head,tail);
result[M-1] = (new Transformations()).r_sum(subZ,subW);
return result;
} // t4
/**
* Evaluates a solution
* @param solution The solution to evaluate
* @throws JMException
*/
public final void evaluate(Solution solution) throws JMException {
float [] variables = new float[getNumberOfVariables()];
Variable[] dv = solution.getDecisionVariables();
for (int i = 0; i < getNumberOfVariables(); i++) {
variables[i] = (float)dv[i].getValue();
}
float [] f = evaluate(variables);
for (int i = 0; i < f.length; i++) {
solution.setObjective(i,f[i]);
}
} //evaluate
} // WFG1