// Utils.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.metaheuristics.moead;
/**
* Utilities methods to used by MOEA/D
*/
public class Utils {
public static double distVector(double[] vector1, double[] vector2) {
int dim = vector1.length;
double sum = 0;
for (int n = 0; n < dim; n++) {
sum += (vector1[n] - vector2[n]) * (vector1[n] - vector2[n]);
}
return Math.sqrt(sum);
} // distVector
public static void minFastSort(double x[], int idx[], int n, int m) {
for (int i = 0; i < m; i++) {
for (int j = i + 1; j < n; j++) {
if (x[i] > x[j]) {
double temp = x[i];
x[i] = x[j];
x[j] = temp;
int id = idx[i];
idx[i] = idx[j];
idx[j] = id;
} // if
}
} // for
} // minFastSort
public static void randomPermutation(int[] perm, int size) {
int[] index = new int[size];
boolean[] flag = new boolean[size];
for (int n = 0; n < size; n++) {
index[n] = n;
flag[n] = true;
}
int num = 0;
while (num < size) {
int start = jmetal.util.PseudoRandom.randInt(0, size - 1);
//int start = int(size*nd_uni(&rnd_uni_init));
while (true) {
if (flag[start]) {
perm[num] = index[start];
flag[start] = false;
num++;
break;
}
if (start == (size - 1)) {
start = 0;
} else {
start++;
}
}
} // while
} // randomPermutation
}