com.chinnu.churndetection.fuzzykmeans.FuzzyKMeansMapper.java Source code

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Here is the source code for com.chinnu.churndetection.fuzzykmeans.FuzzyKMeansMapper.java

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package com.chinnu.churndetection.fuzzykmeans;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashMap;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapreduce.Mapper;

import com.chinnu.churndetection.utils.Constants;
import com.chinnu.churndetection.utils.DistanceComparator;
import com.chinnu.churndetection.utils.MRLogger;
import com.chinnu.churndetection.utils.Vector;

/**
 *
 * @author libin
 */
public class FuzzyKMeansMapper extends Mapper<LongWritable, Text, IntWritable, Vector> {

    String CENTERS;
    int STARTINDEX;
    int ENDINDEX;
    int CLASSINDEX;
    int DATALENGTH;
    double m = 1.2d;

    @Override
    protected void setup(Mapper<LongWritable, Text, IntWritable, Vector>.Context context)
            throws IOException, InterruptedException {

        Configuration conf = context.getConfiguration();

        CENTERS = conf.get(Constants.CENTER_TEXT);
        STARTINDEX = conf.getInt(Constants.STARTINDEX, 0);
        ENDINDEX = conf.getInt(Constants.ENDINDEX, 0);
        CLASSINDEX = conf.getInt(Constants.CLASSINDEX, 0);
        DATALENGTH = ENDINDEX - STARTINDEX;
        super.setup(context);
    }

    @Override
    protected void map(LongWritable key, Text value,
            Mapper<LongWritable, Text, IntWritable, Vector>.Context context)
            throws IOException, InterruptedException {

        HashMap<Integer, double[]> centers = new HashMap<>();
        int idx = 0;
        String[] lineSplit = CENTERS.split("\n");
        for (int j = 0; j < lineSplit.length; j++) {
            String line = lineSplit[j];
            double[] center = new double[DATALENGTH];
            String[] split = line.split(",");
            for (int i = 0; i < DATALENGTH; i++) {
                center[i] = Double.parseDouble(split[i]);
            }
            centers.put(idx++, center);

        }

        String line = value.toString();
        String[] split = line.split(",");
        double[] data = new double[DATALENGTH];

        for (int i = STARTINDEX; i < ENDINDEX; i++) {
            data[i - STARTINDEX] = Double.parseDouble(split[i]);
        }

        double etahSum = 0d;
        for (Integer cKey : centers.keySet()) {
            double[] cenetr = centers.get(cKey);
            double dist = DistanceComparator.findDistance(cenetr, data);
            double inv_dist = 1 / dist;
            double pow = 1 / (m - 1);
            double etah = Math.pow(inv_dist, pow);
            etahSum += etah;
        }

        String className = split[CLASSINDEX];

        Vector vector = new Vector();
        vector.setData(data);
        vector.setClassName(className);

        vector.setIndex(Integer.parseInt(split[0]));

        int nearCenter = DistanceComparator.findMinimumDistance(data, centers);

        double[] cenetr = centers.get(nearCenter);
        double dist = DistanceComparator.findDistance(cenetr, data);
        double inv_dist = 1 / dist;
        double pow = 1 / (m - 1);
        double etah = Math.pow(inv_dist, pow);

        double mew = etah / etahSum;
        vector.setMew(mew);
        MRLogger.Log("Mew : " + mew);

        IntWritable k = new IntWritable(nearCenter);
        context.write(k, vector);
    }

}