Example usage for org.apache.mahout.math DenseVector zSum

Introduction

In this page you can find the example usage for org.apache.mahout.math DenseVector zSum.

Prototype

@Override
    public double zSum() 

Source Link

Usage

From source file:root.hap.availability.AvailabilityReducer.java

License:Apache License

private void updateAvailability(Context context, DenseVector A, DenseVector R, DenseVector S, DenseVector P,
        DenseVector C, int reducerColNum, int reducerLevelNum, int N, String availability)
        throws IOException, InterruptedException {

    DenseVector oldA = A.clone();/*from  w w w  . ja va  2  s  .  c o m*/

    // get positive values into RPositive
    DenseVector RPositive = R.clone();
    for (int rowNum = 0; rowNum < N; rowNum++) {
        double RValue = RPositive.get(rowNum);
        if (RValue < 0) {
            RPositive.setQuick(rowNum, 0);
        }
    }

    // reset diagonal value from R
    RPositive.setQuick(reducerColNum, R.get(reducerColNum));

    // sum R Positive values
    double RPSum = RPositive.zSum();

    double CVal = C.get(0);
    double PVal = P.get(0);

    double CHat = CVal + PVal;

    // sum together CHat and RPSum into a vector
    A.assign(CHat + RPSum);

    A = (DenseVector) A.minus(RPositive);

    for (int rowNum = 0; rowNum < N; rowNum++) {

        if (rowNum == reducerColNum) {
            continue;
        }

        double value = A.get(rowNum) < 0 ? A.get(rowNum) : 0;

        A.setQuick(rowNum, value);
    }

    double lambda = context.getConfiguration().getFloat("lambda", 0);
    A = (DenseVector) A.times(1 - lambda);
    oldA = (DenseVector) oldA.times(lambda);
    A = (DenseVector) A.plus(oldA);

    VectorWritable AWritable = new VectorWritable(A);

    context.write(new Text(reducerColNum + "\t" + reducerLevelNum + "\t" + availability), AWritable);

}

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