Examples of org.apache.commons.math.stat.descriptive.moment.SecondMoment

Package org.apache.commons.math.stat.descriptive.moment

Examples of org.apache.commons.math.stat.descriptive.moment.SecondMoment

org.apache.commons.math.stat.descriptive.moment.SecondMoment
Computes a statistic related to the Second Central Moment. Specifically, what is computed is the sum of squared deviations from the sample mean.
The following recursive updating formula is used:

Let
- dev = (current obs - previous mean)
- n = number of observations (including current obs)
Then

new value = old value + dev^2 * (n -1) / n.

Returns Double.NaN if no data values have been added and returns 0 if there is just one value in the data set.

Note that this implementation is not synchronized. If multiple threads access an instance of this class concurrently, and at least one of the threads invokes the increment() or clear() method, it must be synchronized externally.
@version $Revision: 811685 $ $Date: 2009-09-05 19:36:48 +0200 (sam. 05 sept. 2009) $

    }


    public void testMomentSmallSamples() {
        UnivariateStatistic stat = getUnivariateStatistic();
        if (stat instanceof SecondMoment) {
            SecondMoment moment = (SecondMoment) getUnivariateStatistic();
            assertTrue(Double.isNaN(moment.getResult()));
            moment.increment(1d);
            assertEquals(0d, moment.getResult(), 0);
        }
    }

View Full Code Here

     */
    public double calculateTotalSumOfSquares() {
        if (isNoIntercept()) {
            return StatUtils.sumSq(Y.getData());
        } else {
            return new SecondMoment().evaluate(Y.getData());
        }
    }

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    }
    
    public void testMomentSmallSamples() {
        UnivariateStatistic stat = getUnivariateStatistic();
        if (stat instanceof SecondMoment) {
            SecondMoment moment = (SecondMoment) getUnivariateStatistic();
            assertTrue(Double.isNaN(moment.getResult()));
            moment.increment(1d);
            assertEquals(0d, moment.getResult(), 0);
        }
    }

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        sumsq = new SumOfSquares();
        min = new Min();
        max = new Max();
        sumLog = new SumOfLogs();
        geoMean = new GeometricMean();
        secondMoment = new SecondMoment();
    }

View Full Code Here

    }


    public void testMomentSmallSamples() {
        UnivariateStatistic stat = getUnivariateStatistic();
        if (stat instanceof SecondMoment) {
            SecondMoment moment = (SecondMoment) getUnivariateStatistic();
            assertTrue(Double.isNaN(moment.getResult()));
            moment.increment(1d);
            assertEquals(0d, moment.getResult(), 0);
        }
    }

View Full Code Here

    }
    
    public void testMomentSmallSamples() {
        UnivariateStatistic stat = getUnivariateStatistic();
        if (stat instanceof SecondMoment) {
            SecondMoment moment = (SecondMoment) getUnivariateStatistic();
            assertTrue(Double.isNaN(moment.getResult()));
            moment.increment(1d);
            assertEquals(0d, moment.getResult(), 0);
        }
    }

View Full Code Here

        sumsq = new SumOfSquares();
        min = new Min();
        max = new Max();
        sumLog = new SumOfLogs();
        geoMean = new GeometricMean();
        secondMoment = new SecondMoment();
    }

View Full Code Here

    }
    
    public void testMomentSmallSamples() {
        UnivariateStatistic stat = getUnivariateStatistic();
        if (stat instanceof SecondMoment) {
            SecondMoment moment = (SecondMoment) getUnivariateStatistic();
            assertTrue(Double.isNaN(moment.getResult()));
            moment.increment(1d);
            assertEquals(0d, moment.getResult(), 0);
        }
    }

View Full Code Here

    }
    
    public void testMomentSmallSamples() {
        UnivariateStatistic stat = getUnivariateStatistic();
        if (stat instanceof SecondMoment) {
            SecondMoment moment = (SecondMoment) getUnivariateStatistic();
            assertTrue(Double.isNaN(moment.getResult()));
            moment.increment(1d);
            assertEquals(0d, moment.getResult(), 0);
        }
    }

View Full Code Here

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Related Classes of org.apache.commons.math.stat.descriptive.moment.SecondMoment

org.apache.commons.math.stat.descriptive.StorelessUnivariateStatisticAbstractTest

org.apache.commons.math.stat.descriptive.SummaryStatisticsImpl

org.apache.commons.math.stat.regression.OLSMultipleLinearRegression

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