Package org.apache.commons.math.stat.ranking

Class 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)
    NaNStrategyTiesStrategy 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 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