/*
* Apache License
* Version 2.0, January 2004
* http://www.apache.org/licenses/
*
* Copyright 2013 Aurelian Tutuianu
* Copyright 2014 Aurelian Tutuianu
* Copyright 2015 Aurelian Tutuianu
* Copyright 2016 Aurelian Tutuianu
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package rapaio.data.filter.frame;
import rapaio.core.RandomSource;
import rapaio.data.Frame;
import rapaio.data.Mapping;
import rapaio.data.VRange;
import rapaio.data.filter.FFilter;
import java.util.ArrayList;
import java.util.List;
/**
* Created by <a href="mailto:padreati@yahoo.com">Aurelian Tutuianu</a> at 12/5/14.
*/
public class FFShuffle extends AbstractFF {
private static final long serialVersionUID = 3868876807602578584L;
public FFShuffle() {
super(VRange.all());
}
@Override
public FFilter newInstance() {
return new FFShuffle();
}
@Override
public void train(Frame df) {
parse(df);
}
@Override
public Frame apply(Frame df) {
List<Integer> mapping = new ArrayList<>();
for (int i = 0; i < df.rowCount(); i++) {
mapping.add(i);
}
for (int i = mapping.size(); i > 1; i--) {
mapping.set(i - 1, mapping.set(RandomSource.nextInt(i), mapping.get(i - 1)));
}
return df.mapRows(Mapping.wrap(mapping));
}
}