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 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: 1006299 $ $Date: 2010-10-10 16:47:17 +0200 (dim. 10 oct. 2010) $

Constructor Summary

AbstractUnivariateStatistic()

Method Summary

abstract UnivariateStatistic	copy() Returns a copy of the statistic with the same internal state.
double	evaluate() Returns the result of evaluating the statistic over the stored data.
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.
double[]	getData() Get a copy of the stored data array.
protected double[]	getDataRef() Get a reference to the stored data array.
void	setData(double[] values) Set the data array.
void	setData(double[] values, int begin, int length) Set the data 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

setData

public void setData(double[] values)

Set the data array.

The stored value is a copy of the parameter array, not the array itself

Parameters:

values - data array to store (may be null to remove stored data)

See Also:

evaluate()

getData

public double[] getData()

Get a copy of the stored data array.

Returns:

copy of the stored data array (may be null)

getDataRef

protected double[] getDataRef()

Get a reference to the stored data array.

Returns:

reference to the stored data array (may be null)

setData

public void setData(double[] values,
                    int begin,
                    int length)

Set the data array.

Parameters:

values - data array to store

begin - the index of the first element to include

length - the number of elements to include

See Also:

evaluate()

evaluate

public double evaluate()

Returns the result of evaluating the statistic over the stored data.

The stored array is the one which was set by previous calls to

Returns:

the value of the statistic applied to the stored data

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:

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:

IllegalArgumentException - if the indices are invalid or the array is null

Since:

2.1