Example usage for org.apache.mahout.cf.taste.impl.common RunningAverageAndStdDev getStandardDeviation

Introduction

In this page you can find the example usage for org.apache.mahout.cf.taste.impl.common RunningAverageAndStdDev getStandardDeviation.

Prototype

double getStandardDeviation();

Source Link

Usage

From source file:recommender.GenericRecommenderIRStatsEvaluatorCustom.java

License:Apache License

private static double computeThreshold(PreferenceArray prefs) {
    if (prefs.length() < 2) {
        // Not enough data points -- return a threshold that allows everything
        return Double.NEGATIVE_INFINITY;
    }/*from   w  ww. ja v a2  s  .co  m*/
    RunningAverageAndStdDev stdDev = new FullRunningAverageAndStdDev();
    int size = prefs.length();
    for (int i = 0; i < size; i++) {
        stdDev.addDatum(prefs.getValue(i));
    }
    return stdDev.getAverage() + stdDev.getStandardDeviation();
}

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