org.apache.commons.math3.stat.descriptive.moment

## Class GeometricMean

• All Implemented Interfaces:
Serializable, StorelessUnivariateStatistic, UnivariateStatistic, MathArrays.Function

public class GeometricMean
extends AbstractStorelessUnivariateStatistic
implements Serializable
Returns the geometric mean of the available values.

Uses a SumOfLogs instance to compute sum of logs and returns exp( 1/n (sum of logs) ). Therefore,

• If any of values are < 0, the result is NaN.
• If all values are non-negative and less than Double.POSITIVE_INFINITY, but at least one value is 0, the result is 0.
• If both Double.POSITIVE_INFINITY and Double.NEGATIVE_INFINITY are among the values, the result is NaN.

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:
$Id: GeometricMean.java 1416643 2012-12-03 19:37:14Z tn$