## org.apache.commons.math.stat.descriptive
Class AbstractUnivariateStatistic

    java.lang.Object
      org.apache.commons.math.stat.descriptive.AbstractUnivariateStatistic

All Implemented Interfaces:
  UnivariateStatistic

Direct Known Subclasses:
  AbstractStorelessUnivariateStatistic, Percentile, SemiVariance

    public abstract class AbstractUnivariateStatistic

extends java.lang.Object
implements UnivariateStatistic

Abstract base class for all implementations of the `UnivariateStatistic` interface.

Provides a default implementation of `evaluate(double[]),` delegating to `evaluate(double[], int, int)` in the natural way.

Also includes a `test` method that performs generic parameter validation for the `evaluate` methods.

Version:
  $Revision: 894705 $ $Date: 2009-12-30 15:24:54 -0500 (Wed, 30 Dec 2009) $

Constructor Summary
`AbstractUnivariateStatistic()`

Method Summary
`abstract UnivariateStatistic` `copy()` Returns a copy of the statistic with the same internal state.
`double` `evaluate(double[] values)` Returns the result of evaluating the statistic over the input array.
`abstract double` `evaluate(double[] values, int begin, int length)` Returns the result of evaluating the statistic over the specified entries in the input array.
`protected boolean` `test(double[] values, double[] weights, int begin, int length)` This method is used by `evaluate(double[], double[], int, int)` methods to verify that the begin and length parameters designate a subarray of positive length and the weights are all non-negative, non-NaN, finite, and not all zero.
`protected boolean` `test(double[] values, int begin, int length)` This method is used by `evaluate(double[], int, int)` methods to verify that the input parameters designate a subarray of positive length.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### AbstractUnivariateStatistic

    public AbstractUnivariateStatistic()

Method Detail

### evaluate

    public double evaluate(double[] values)

  Returns the result of evaluating the statistic over the input array.

  Specified by:
    `evaluate` in interface `UnivariateStatistic`
  Parameters:
    `values` - input array
  Returns:
    the value of the statistic applied to the input array

### evaluate

    public abstract double evaluate(double[] values,
                                    int begin,
                                    int length)

  Returns the result of evaluating the statistic over the specified entries in the input array.

  Specified by:
    `evaluate` in interface `UnivariateStatistic`
  Parameters:
    `values` - the input array
    `begin` - the index of the first element to include
    `length` - the number of elements to include
  Returns:
    the value of the statistic applied to the included array entries

### copy

    public abstract UnivariateStatistic copy()

  Returns a copy of the statistic with the same internal state.

  Specified by:
    `copy` in interface `UnivariateStatistic`
  Returns:
    a copy of the statistic

### test

    protected boolean test(double[] values,
                           int begin,
                           int length)

  This method is used by `evaluate(double[], int, int)` methods to verify that the input parameters designate a subarray of positive length.

  - returns `true` iff the parameters designate a subarray of positive length
  - throws `IllegalArgumentException` if the array is null or or the indices are invalid
  - returns `false`
  if the array is non-null, but `length` is 0.

  Parameters:
    `values` - the input array
    `begin` - index of the first array element to include
    `length` - the number of elements to include
  Returns:
    true if the parameters are valid and designate a subarray of positive length
  Throws:
    `java.lang.IllegalArgumentException` - if the indices are invalid or the array is null

### test

    protected boolean test(double[] values,
                           double[] weights,
                           int begin,
                           int length)

  This method is used by `evaluate(double[], double[], int, int)` methods to verify that the begin and length parameters designate a subarray of positive length and the weights are all non-negative, non-NaN, finite, and not all zero.

  - returns `true` iff the parameters designate a subarray of positive length and the weights array contains legitimate values.
  - throws `IllegalArgumentException` if any of the following are true:
    - the values array is null
    - the weights array is null
    - the weights array does not have the same length as the values array
    - the weights array contains one or more infinite values
    - the weights array contains one or more NaN values
    - the weights array contains negative values
    - the start and length arguments do not determine a valid array
  - returns `false`
  if the array is non-null, but `length` is 0.

  Parameters:
    `values` - the input array
    `weights` - the weights array
    `begin` - index of the first array element to include
    `length` - the number of elements to include
  Returns:
    true if the parameters are valid and designate a subarray of positive length
  Throws:
    `java.lang.IllegalArgumentException` - if the indices are invalid or the array is null
  Since:
    2.1

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