NumericalVarStats.java

/*
 * 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 ml.shifu.shifu.udf.stats;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;

import ml.shifu.shifu.container.obj.ColumnConfig;
import ml.shifu.shifu.container.obj.ModelConfig;
import ml.shifu.shifu.udf.CalculateStatsUDF;
import ml.shifu.shifu.util.CommonUtils;

import org.apache.commons.lang.StringUtils;
import org.apache.pig.backend.executionengine.ExecException;
import org.apache.pig.data.DataBag;
import org.apache.pig.data.Tuple;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * NumericalVarStats class
 */
public class NumericalVarStats extends AbstractVarStats {

    private static Logger log = LoggerFactory.getLogger(NumericalVarStats.class);

    public NumericalVarStats(ModelConfig modelConfig, ColumnConfig columnConfig, Double valueThreshold) {
        super(modelConfig, columnConfig, valueThreshold);
    }

    /*
     * (non-Javadoc)
     * 
     * @see ml.shifu.shifu.udf.stats.AbstractVarStats#runVarStats(java.lang.String, org.apache.pig.data.DataBag)
     */
    @Override
    public void runVarStats(String binningInfo, DataBag databag) throws ExecException {
        String[] binningDataArr = StringUtils.split(binningInfo, CalculateStatsUDF.CATEGORY_VAL_SEPARATOR);

        log.info("Column Name - " + this.columnConfig.getColumnName() + ", Column Bin Length - "
                + binningDataArr.length);

        List<Double> binBoundary = new ArrayList<Double>();
        for(String binningElement: binningDataArr) {
            binBoundary.add(Double.valueOf(binningElement));
        }

        columnConfig.setBinBoundary(binBoundary);
        statsNumericalColumnInfo(databag, columnConfig);
    }

    /**
     * @param databag
     * @param columnConfig
     * @throws ExecException
     */
    private void statsNumericalColumnInfo(DataBag databag, ColumnConfig columnConfig) throws ExecException {
        // The last bin is for missingOrInvalid values
        Integer[] binCountPos = new Integer[columnConfig.getBinBoundary().size() + 1];
        Integer[] binCountNeg = new Integer[columnConfig.getBinBoundary().size() + 1];
        Double[] binWeightCountPos = new Double[columnConfig.getBinBoundary().size() + 1];
        Double[] binWeightCountNeg = new Double[columnConfig.getBinBoundary().size() + 1];
        int lastBinIndex = columnConfig.getBinBoundary().size();

        initializeZeroArr(binCountPos);
        initializeZeroArr(binCountNeg);
        initializeZeroArr(binWeightCountPos);
        initializeZeroArr(binWeightCountNeg);

        boolean isMissingValue = false;
        boolean isInvalidValue = false;
        Iterator<Tuple> iterator = databag.iterator();
        while(iterator.hasNext()) {
            isMissingValue = false;
            isInvalidValue = false;
            Tuple element = iterator.next();

            if(element.size() < 4) {
                continue;
            }

            Object value = element.get(1);
            String tag = CommonUtils.trimTag((String) element.get(2));
            Double weight = (Double) element.get(3);

            double colVal = 0.0;
            String str = null;
            if(value == null || StringUtils.isBlank(value.toString())) {
                // TODO check missing value list in ModelConfig??
                missingValueCnt++;
                isMissingValue = true;
            } else {
                str = StringUtils.trim(value.toString());
                try {
                    colVal = Double.parseDouble(str);
                } catch (Exception e) {
                    invalidValueCnt++;
                    isInvalidValue = true;
                }
            }

            if(isInvalidValue || isMissingValue) {
                if(modelConfig.getPosTags().contains(tag)) {
                    increaseInstCnt(binCountPos, lastBinIndex);
                    increaseInstCnt(binWeightCountPos, lastBinIndex, weight);
                } else if(modelConfig.getNegTags().contains(tag)) {
                    increaseInstCnt(binCountNeg, lastBinIndex);
                    increaseInstCnt(binWeightCountNeg, lastBinIndex, weight);
                }
            } else {
                streamStatsCalculator.addData(colVal);
                // binning.addData(colVal);
                int binNum = CommonUtils.getBinNum(columnConfig, str);
                if(binNum == -1) {
                    throw new RuntimeException("binNum should not be -1 to this step.");
                }
                if(modelConfig.getPosTags().contains(tag)) {
                    increaseInstCnt(binCountPos, binNum);
                    increaseInstCnt(binWeightCountPos, binNum, weight);
                } else if(modelConfig.getNegTags().contains(tag)) {
                    increaseInstCnt(binCountNeg, binNum);
                    increaseInstCnt(binWeightCountNeg, binNum, weight);
                }
            }
        }

        columnConfig.setBinCountPos(Arrays.asList(binCountPos));
        columnConfig.setBinCountNeg(Arrays.asList(binCountNeg));
        columnConfig.setBinWeightedPos(Arrays.asList(binWeightCountPos));
        columnConfig.setBinWeightedNeg(Arrays.asList(binWeightCountNeg));

        columnConfig.setMax(streamStatsCalculator.getMax());
        columnConfig.setMean(streamStatsCalculator.getMean());
        columnConfig.setMin(streamStatsCalculator.getMin());
        columnConfig.setMedian(streamStatsCalculator.getMedian());
        columnConfig.setStdDev(streamStatsCalculator.getStdDev());

        // Currently, invalid value will be regarded as missing
        columnConfig.setMissingCnt(missingValueCnt + invalidValueCnt);
        columnConfig.setTotalCount(databag.size());
        columnConfig.setMissingPercentage(((double) columnConfig.getMissingCount()) / columnConfig.getTotalCount());
        columnConfig.getColumnStats().setSkewness(streamStatsCalculator.getSkewness());
        columnConfig.getColumnStats().setKurtosis(streamStatsCalculator.getKurtosis());
        calculateBinPosRateAndAvgScore();
    }
}