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

Generic univariate summary statistic objects.

See:
Description

Interface Summary
StatisticalMultivariateSummary: Reporting interface for basic multivariate statistics.
StatisticalSummary: Reporting interface for basic univariate statistics.
StorelessUnivariateStatistic: Extends the definition of `UnivariateStatistic` with `StorelessUnivariateStatistic.increment(double)` and `StorelessUnivariateStatistic.incrementAll(double[])` methods for adding values and updating internal state.
UnivariateStatistic: Base interface implemented by all statistics.
WeightedEvaluation: Weighted evaluation for statistics.

Class Summary
AbstractStorelessUnivariateStatistic: Abstract implementation of the `StorelessUnivariateStatistic` interface.
AbstractUnivariateStatistic: Abstract base class for all implementations of the `UnivariateStatistic` interface.
AggregateSummaryStatistics: An aggregator for `SummaryStatistics` from several data sets or data set partitions.
AggregateSummaryStatistics.AggregatingSummaryStatistics: A SummaryStatistics that also forwards all values added to it to a second `SummaryStatistics` for aggregation.
DescriptiveStatistics: Maintains a dataset of values of a single variable and computes descriptive statistics based on stored data.
MultivariateSummaryStatistics: Computes summary statistics for a stream of n-tuples added using the `addValue` method.
StatisticalSummaryValues: Value object representing the results of a univariate statistical summary.
SummaryStatistics: Computes summary statistics for a stream of data values added using the `addValue` method.
SynchronizedDescriptiveStatistics: Implementation of `DescriptiveStatistics` that is safe to use in a multithreaded environment.
SynchronizedMultivariateSummaryStatistics: Implementation of `MultivariateSummaryStatistics` that is safe to use in a multithreaded environment.
SynchronizedSummaryStatistics: Implementation of `SummaryStatistics` that is safe to use in a multithreaded environment.

## Package org.apache.commons.math.stat.descriptive Description

Generic univariate summary statistic objects.

### UnivariateStatistic API Usage Examples:

#### UnivariateStatistic:

`/* evaluation approach */
double[] values = new double[] { 1, 2, 3, 4, 5 };
UnivariateStatistic stat = new Mean();
System.out.println("mean = " + stat.evaluate(values));
`

#### StorelessUnivariateStatistic:

`/* incremental approach */
double[] values = new double[] { 1, 2, 3, 4, 5 };
StorelessUnivariateStatistic stat = new Mean();
System.out.println("mean before adding a value is NaN = " + stat.getResult());
for (int i = 0; i < values.length; i++) {
stat.increment(values[i]);
System.out.println("current mean = " + stat2.getResult());
}
stat.clear();
System.out.println("mean after clear is NaN = " + stat.getResult());`

Copyright (c) 2003-2013 Apache Software Foundation