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

Field Summary

Fields

Modifier and Type	Field and Description
private double[]	storedData Stored data.

Constructor Summary

Constructors

Constructor and Description
AbstractUnivariateStatistic()

Method Summary

Modifier and Type	Method and Description
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

Field Detail

storedData

private double[] storedData

Stored data.

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:

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