/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2014 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.features.transformation;

import java.util.Iterator;

import Jama.Matrix;

import com.rapidminer.example.Attribute;
import com.rapidminer.example.Example;
import com.rapidminer.example.ExampleSet;
import com.rapidminer.operator.OperatorDescription;

/**
 * This class is completely unnecessary and is only kept for compatibility reasons.
 * The class hierarchy is complete nonsense and will be dropped with one of the next
 * versions. So if you implement using this class, please implement this little code fragment
 * below again or build a more fitting class hierarchy.
 * 
 * This class represents an abstract framework for performing dimensionality reduction using the JAMA package.
 * 
 * @author Michael Wurst, Ingo Mierswa
 * 
 */
@Deprecated
public abstract class JamaDimensionalityReduction extends DimensionalityReducer {

    public JamaDimensionalityReduction(OperatorDescription description) {
        super(description);
    }

    protected abstract Matrix callMatrixMethod(ExampleSet es, int dimension, Matrix in);

    @Override
    protected double[][] dimensionalityReduction(ExampleSet es, int dimensions) {
        // encode matrix
        Matrix in = new Matrix(es.size(), es.getAttributes().size());
        Iterator<Example> er = es.iterator();
        int count = 0;
        while (er.hasNext()) {
            Example e = er.next();
            int i = 0;
            for (Attribute attribute : e.getAttributes()) {
                in.set(count, i++, e.getValue(attribute));
            }

            count++;
        }
        Matrix result = callMatrixMethod(es, dimensions, in);

        // decode matrix
        return result.getArray();
    }
}