/**
* Copyright (C) 2001-2017 by RapidMiner and the contributors
*
* Complete list of developers available at our web site:
*
* http://rapidminer.com
*
* This program is free software: you can redistribute it and/or modify it under the terms of the
* GNU Affero 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
* Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License along with this program.
* If not, see http://www.gnu.org/licenses/.
*/
package com.rapidminer.operator.preprocessing.filter;
import com.rapidminer.example.ExampleSet;
import com.rapidminer.example.set.SortedExampleSet;
import com.rapidminer.operator.OperatorDescription;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.operator.annotation.ResourceConsumptionEstimator;
import com.rapidminer.operator.preprocessing.AbstractDataProcessing;
import com.rapidminer.parameter.ParameterType;
import com.rapidminer.tools.OperatorResourceConsumptionHandler;
import com.rapidminer.tools.RandomGenerator;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
* This operator creates a new, shuffled ExampleSet by making creating a shuffled view using a
* {@link SortedExampleSet}
*
* @author Sebastian Land, Ingo Mierswa
*/
public class PermutationOperator extends AbstractDataProcessing {
public PermutationOperator(OperatorDescription description) {
super(description);
}
@Override
public ExampleSet apply(ExampleSet exampleSet) throws OperatorException {
ArrayList<Integer> indicesCollection = new ArrayList<Integer>(exampleSet.size());
for (int i = 0; i < exampleSet.size(); i++) {
indicesCollection.add(i);
}
Collections.shuffle(indicesCollection, RandomGenerator.getRandomGenerator(this));
int[] indices = new int[exampleSet.size()];
for (int i = 0; i < exampleSet.size(); i++) {
indices[i] = indicesCollection.get(i);
}
return new SortedExampleSet(exampleSet, indices);
}
@Override
public List<ParameterType> getParameterTypes() {
List<ParameterType> types = super.getParameterTypes();
types.addAll(RandomGenerator.getRandomGeneratorParameters(this));
return types;
}
@Override
public boolean writesIntoExistingData() {
return false;
}
@Override
public ResourceConsumptionEstimator getResourceConsumptionEstimator() {
return OperatorResourceConsumptionHandler.getResourceConsumptionEstimator(getInputPort(), PermutationOperator.class,
null);
}
}