org.ankus.mapreduce.algorithms.preprocessing.normalize.NormalizeMapper.java Source code

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Here is the source code for org.ankus.mapreduce.algorithms.preprocessing.normalize.NormalizeMapper.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.ankus.mapreduce.algorithms.preprocessing.normalize;

import java.io.IOException;

import org.ankus.util.ArgumentsConstants;
import org.ankus.util.CommonMethods;
import org.ankus.util.ConfigurationVariable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;

/**
 * NormalizeMapper
 * @desc mapper class for normalization mr job
 *
 * @version 0.0.1
 * @date : 2013.08.21
 * @author Moonie
 */
public class NormalizeMapper extends Mapper<Object, Text, NullWritable, Text> {

    // delimiter for attribute separation
    private String mDelimiter;
    // attribute index array for normalization
    private int mIndexArr[];
    // value for if no-normalization attributes is remain
    private boolean mRemainFields;
    // attribute index array for do not normalize
    private int mExceptionIndexArr[];

    @Override
    protected void setup(Context context) throws IOException, InterruptedException {
        mDelimiter = context.getConfiguration().get(ArgumentsConstants.DELIMITER, "\t");
        mIndexArr = CommonMethods
                .convertIndexStr2IntArr(context.getConfiguration().get(ArgumentsConstants.TARGET_INDEX, "-1"));
        mExceptionIndexArr = CommonMethods
                .convertIndexStr2IntArr(context.getConfiguration().get(ArgumentsConstants.EXCEPTION_INDEX, "-1"));

        if (context.getConfiguration().get(ArgumentsConstants.REMAIN_FIELDS, "true").equals("true")) {
            mRemainFields = true;
        } else {
            mRemainFields = false;
        }
    }

    @Override
    protected void map(Object key, Text value, Context context) throws IOException, InterruptedException {
        String[] columns = value.toString().split(mDelimiter);

        String writeVal = "";
        for (int i = 0; i < columns.length; i++) {
            if (CommonMethods.isContainIndex(mIndexArr, i, true)) {
                if (!CommonMethods.isContainIndex(mExceptionIndexArr, i, false)) {
                    if (i > 0)
                        writeVal += mDelimiter;

                    String minMax[] = context.getConfiguration()
                            .get(ConfigurationVariable.MINMAX_VALUE + "_" + i, "0,0").split(",");

                    double val1 = Double.parseDouble(columns[i]) - Double.parseDouble(minMax[0]);
                    double val2 = Double.parseDouble(minMax[1]) - Double.parseDouble(minMax[0]);

                    if ((val2 == 0) || (val2 == 0))
                        writeVal += "0";
                    else
                        writeVal += "" + (val1 / val2);
                } else if (mRemainFields) {
                    if (i > 0)
                        writeVal += mDelimiter;
                    writeVal += columns[i];
                }
            } else if (mRemainFields) {
                if (i > 0)
                    writeVal += mDelimiter;
                writeVal += columns[i];
            }
        }
        context.write(NullWritable.get(), new Text(writeVal.trim()));
    }

    @Override
    protected void cleanup(Context context) throws IOException, InterruptedException {
    }
}