/**
* Copyright (C) 2010-2017 Gordon Fraser, Andrea Arcuri and EvoSuite
* contributors
*
* This file is part of EvoSuite.
*
* EvoSuite 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 3.0 of the License, or
* (at your option) any later version.
*
* EvoSuite 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 Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with EvoSuite. If not, see <http://www.gnu.org/licenses/>.
*/
package org.evosuite.ga.operators.crossover;
import org.evosuite.ga.Chromosome;
import org.evosuite.ga.ConstructionFailedException;
import org.evosuite.utils.Randomness;
/**
* Cross over individuals at relative position
*
* @author Gordon Fraser
*/
public class SinglePointRelativeCrossOver extends CrossOverFunction {
private static final long serialVersionUID = -5320348525459502224L;
/**
* {@inheritDoc}
*
* The splitting point is not an absolute value but a relative value (eg, at
* position 70% of n). For example, if n1=10 and n2=20 and splitting point
* is 70%, we would have position 7 in the first and 14 in the second.
* Therefore, the offspring d have n<=max(n1,n2)
*/
@Override
public void crossOver(Chromosome parent1, Chromosome parent2)
throws ConstructionFailedException {
if (parent1.size() < 2 || parent2.size() < 2) {
return;
}
Chromosome t1 = parent1.clone();
Chromosome t2 = parent2.clone();
// Choose a position in the middle
float splitPoint = Randomness.nextFloat();
int pos1 = ((int) Math.floor((t1.size() - 1) * splitPoint)) + 1;
int pos2 = ((int) Math.floor((t2.size() - 1) * splitPoint)) + 1;
parent1.crossOver(t2, pos1, pos2);
parent2.crossOver(t1, pos2, pos1);
}
}