org.openml.webapplication.fantail.dc.statistical.ClassAtt.java Source code

Introduction

Here is the source code for org.openml.webapplication.fantail.dc.statistical.ClassAtt.java

Source

/*
 *  Webapplication - Java library that runs on OpenML servers
 *  Copyright (C) 2014 
 *  @author Jan N. van Rijn (j.n.van.rijn@liacs.leidenuniv.nl)
 *  @author Quan Sun (quan.sun.nz@gmail.com)
 *  
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU 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 General Public License for more details.
 *  
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *  
 */
package org.openml.webapplication.fantail.dc.statistical;

import java.util.HashMap;
import java.util.Map;

import org.openml.webapplication.fantail.dc.Characterizer;

import weka.core.Instance;
import weka.core.Instances;

public class ClassAtt extends Characterizer {

    protected final String[] ids = new String[] { "ClassCount", "PositivePercentage", "NegativePercentage" };

    @Override
    public String[] getIDs() {
        return ids;
    }

    @Override
    public Map<String, Double> characterize(Instances instances) {

        int pCount = 0;
        int nCount = 0;

        int[] counts = new int[instances.numClasses()];
        for (int i = 0; i < instances.numInstances(); i++) {
            Instance instance = instances.instance(i);
            counts[(int) instance.classValue()]++;
        }

        pCount = counts[weka.core.Utils.minIndex(counts)];
        nCount = counts[weka.core.Utils.maxIndex(counts)];

        Map<String, Double> qualities = new HashMap<String, Double>();
        qualities.put(ids[0], instances.numClasses() * 1.0);
        qualities.put(ids[1], 1.0 * pCount / instances.numInstances());
        qualities.put(ids[2], 1.0 * nCount / instances.numInstances());
        return qualities;
    }
}