org.apache.commons.math.stat.ranking

Class NaturalRanking

java.lang.Object

org.apache.commons.math.stat.ranking.NaturalRanking

All Implemented Interfaces:

RankingAlgorithm

public class NaturalRanking
extends java.lang.Object
implements RankingAlgorithm

Ranking based on the natural ordering on doubles.

NaNs are treated according to the configured NaNStrategy and ties are handled using the selected TiesStrategy. Configuration settings are supplied in optional constructor arguments. Defaults are NaNStrategy.MAXIMAL and TiesStrategy.AVERAGE, respectively. When using TiesStrategy.RANDOM, a RandomGenerator may be supplied as a constructor argument.

Examples:

Input data: (20, 17, 30, 42.3, 17, 50, Double.NaN, Double.NEGATIVE_INFINITY, 17)
NaNStrategy	TiesStrategy	rank(data)
default (NaNs maximal)	default (ties averaged)	(5, 3, 6, 7, 3, 8, 9, 1, 3)
default (NaNs maximal)	MINIMUM	(5, 2, 6, 7, 2, 8, 9, 1, 2)
MINIMAL	default (ties averaged)	(6, 4, 7, 8, 4, 9, 1.5, 1.5, 4)
REMOVED	SEQUENTIAL	(5, 2, 6, 7, 3, 8, 1, 4)
MINIMAL	MAXIMUM	(6, 5, 7, 8, 5, 9, 2, 2, 5)

Since:

2.0

Field Summary

Fields

Modifier and Type	Field and Description
static NaNStrategy	DEFAULT_NAN_STRATEGY default NaN strategy
static TiesStrategy	DEFAULT_TIES_STRATEGY default ties strategy

Constructor Summary

Constructors

Constructor and Description
NaturalRanking() Create a NaturalRanking with default strategies for handling ties and NaNs.
NaturalRanking(NaNStrategy nanStrategy) Create a NaturalRanking with the given NaNStrategy.
NaturalRanking(NaNStrategy nanStrategy, RandomGenerator randomGenerator) Create a NaturalRanking with the given NaNStrategy, TiesStrategy.RANDOM and the given source of random data.
NaturalRanking(NaNStrategy nanStrategy, TiesStrategy tiesStrategy) Create a NaturalRanking with the given NaNStrategy and TiesStrategy.
NaturalRanking(RandomGenerator randomGenerator) Create a NaturalRanking with TiesStrategy.RANDOM and the given RandomGenerator as the source of random data.
NaturalRanking(TiesStrategy tiesStrategy) Create a NaturalRanking with the given TiesStrategy.

Method Summary

Modifier and Type	Method and Description
NaNStrategy	getNanStrategy() Return the NaNStrategy
TiesStrategy	getTiesStrategy() Return the TiesStrategy
double[]	rank(double[] data) Rank data using the natural ordering on Doubles, with NaN values handled according to nanStrategy and ties resolved using tiesStrategy.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_NAN_STRATEGY

public static final NaNStrategy DEFAULT_NAN_STRATEGY

default NaN strategy

DEFAULT_TIES_STRATEGY

public static final TiesStrategy DEFAULT_TIES_STRATEGY

default ties strategy

Constructor Detail

NaturalRanking

public NaturalRanking()

Create a NaturalRanking with default strategies for handling ties and NaNs.

NaturalRanking

public NaturalRanking(TiesStrategy tiesStrategy)

Create a NaturalRanking with the given TiesStrategy.

Parameters:

tiesStrategy - the TiesStrategy to use

NaturalRanking

public NaturalRanking(NaNStrategy nanStrategy)

Create a NaturalRanking with the given NaNStrategy.

Parameters:

nanStrategy - the NaNStrategy to use

NaturalRanking

public NaturalRanking(NaNStrategy nanStrategy,
                      TiesStrategy tiesStrategy)

Create a NaturalRanking with the given NaNStrategy and TiesStrategy.

Parameters:

nanStrategy - NaNStrategy to use

tiesStrategy - TiesStrategy to use

NaturalRanking

public NaturalRanking(RandomGenerator randomGenerator)

Create a NaturalRanking with TiesStrategy.RANDOM and the given RandomGenerator as the source of random data.

Parameters:

randomGenerator - source of random data

NaturalRanking

public NaturalRanking(NaNStrategy nanStrategy,
                      RandomGenerator randomGenerator)

Create a NaturalRanking with the given NaNStrategy, TiesStrategy.RANDOM and the given source of random data.

Parameters:

nanStrategy - NaNStrategy to use

randomGenerator - source of random data

Method Detail

getNanStrategy

public NaNStrategy getNanStrategy()

Return the NaNStrategy

Returns:

returns the NaNStrategy

getTiesStrategy

public TiesStrategy getTiesStrategy()

Return the TiesStrategy

Returns:

the TiesStrategy

rank

public double[] rank(double[] data)

Rank data using the natural ordering on Doubles, with NaN values handled according to nanStrategy and ties resolved using tiesStrategy.

Specified by:

rank in interface RankingAlgorithm

Parameters:

data - array to be ranked

Returns:

array of ranks