Package org.apache.commons.math.stat

Class Frequency

  • All Implemented Interfaces:
    java.io.Serializable
    public class Frequency
extends java.lang.Object
implements java.io.Serializable
    Maintains a frequency distribution.

    Accepts int, long, char or Comparable values. New values added must be comparable to those that have been added, otherwise the add method will throw an IllegalArgumentException.

    Integer values (int, long, Integer, Long) are not distinguished by type -- i.e. addValue(Long.valueOf(2)), addValue(2), addValue(2l) all have the same effect (similarly for arguments to getCount, etc.).

    char values are converted by addValue to Character instances. As such, these values are not comparable to integral values, so attempts to combine integral types with chars in a frequency distribution will fail.

    The values are ordered using the default (natural order), unless a Comparator is supplied in the constructor.

    See Also:
    Serialized Form

    • Constructor Summary

      Constructors 
      Constructor Description
      Frequency()
      Default constructor.
      Frequency​(java.util.Comparator<?> comparator)
      Constructor allowing values Comparator to be specified.

    • Method Summary

      All Methods Instance Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      void addValue​(char v)
      Adds 1 to the frequency count for v.
      void addValue​(int v)
      Adds 1 to the frequency count for v.
      void addValue​(long v)
      Adds 1 to the frequency count for v.
      void addValue​(java.lang.Comparable<?> v)
      Adds 1 to the frequency count for v.
      void addValue​(java.lang.Integer v)
      Deprecated.
      to be removed in math 3.0
      void addValue​(java.lang.Object v)
      Deprecated.
      use addValue(Comparable) instead
      void clear()
      Clears the frequency table
      boolean equals​(java.lang.Object obj)
      long getCount​(char v)
      Returns the number of values = v.
      long getCount​(int v)
      Returns the number of values = v.
      long getCount​(long v)
      Returns the number of values = v.
      long getCount​(java.lang.Comparable<?> v)
      Returns the number of values = v.
      long getCount​(java.lang.Object v)
      Deprecated.
      replaced by getCount(Comparable) as of 2.0
      long getCumFreq​(char v)
      Returns the cumulative frequency of values less than or equal to v.
      long getCumFreq​(int v)
      Returns the cumulative frequency of values less than or equal to v.
      long getCumFreq​(long v)
      Returns the cumulative frequency of values less than or equal to v.
      long getCumFreq​(java.lang.Comparable<?> v)
      Returns the cumulative frequency of values less than or equal to v.
      long getCumFreq​(java.lang.Object v)
      Deprecated.
      replaced by getCumFreq(Comparable) as of 2.0
      double getCumPct​(char v)
      Returns the cumulative percentage of values less than or equal to v (as a proportion between 0 and 1).
      double getCumPct​(int v)
      Returns the cumulative percentage of values less than or equal to v (as a proportion between 0 and 1).
      double getCumPct​(long v)
      Returns the cumulative percentage of values less than or equal to v (as a proportion between 0 and 1).
      double getCumPct​(java.lang.Comparable<?> v)
      Returns the cumulative percentage of values less than or equal to v (as a proportion between 0 and 1).
      double getCumPct​(java.lang.Object v)
      Deprecated.
      replaced by getCumPct(Comparable) as of 2.0
      double getPct​(char v)
      Returns the percentage of values that are equal to v (as a proportion between 0 and 1).
      double getPct​(int v)
      Returns the percentage of values that are equal to v (as a proportion between 0 and 1).
      double getPct​(long v)
      Returns the percentage of values that are equal to v (as a proportion between 0 and 1).
      double getPct​(java.lang.Comparable<?> v)
      Returns the percentage of values that are equal to v (as a proportion between 0 and 1).
      double getPct​(java.lang.Object v)
      Deprecated.
      replaced by getPct(Comparable) as of 2.0
      long getSumFreq()
      Returns the sum of all frequencies.
      int getUniqueCount()
      Returns the number of values in the frequency table.
      int hashCode()
      java.lang.String toString()
      Return a string representation of this frequency distribution.
      java.util.Iterator<java.lang.Comparable<?>> valuesIterator()
      Returns an Iterator over the set of values that have been added.

      • Methods inherited from class java.lang.Object

        getClass, notify, notifyAll, wait, wait, wait

    • Constructor Detail

      • Frequency

        public Frequency()
        Default constructor.

      • Frequency

        public Frequency​(java.util.Comparator<?> comparator)
        Constructor allowing values Comparator to be specified.
        Parameters:
        comparator - Comparator used to order values

    • Method Detail

      • toString

        public java.lang.String toString()
        Return a string representation of this frequency distribution.
        Overrides:
        toString in class java.lang.Object
        Returns:
        a string representation.

      • addValue

        @Deprecated
public void addValue​(java.lang.Object v)
        Deprecated.
        use addValue(Comparable) instead
        Adds 1 to the frequency count for v.

        If other objects have already been added to this Frequency, v must be comparable to those that have already been added.

        Parameters:
        v - the value to add.
        Throws:
        java.lang.IllegalArgumentException - if v is not Comparable, or is not comparable with previous entries

      • addValue

        public void addValue​(java.lang.Comparable<?> v)
        Adds 1 to the frequency count for v.

        If other objects have already been added to this Frequency, v must be comparable to those that have already been added.

        Parameters:
        v - the value to add.
        Throws:
        java.lang.IllegalArgumentException - if v is not comparable with previous entries

      • addValue

        public void addValue​(int v)
        Adds 1 to the frequency count for v.
        Parameters:
        v - the value to add.

      • addValue

        @Deprecated
public void addValue​(java.lang.Integer v)
        Deprecated.
        to be removed in math 3.0
        Adds 1 to the frequency count for v.
        Parameters:
        v - the value to add.

      • addValue

        public void addValue​(long v)
        Adds 1 to the frequency count for v.
        Parameters:
        v - the value to add.

      • addValue

        public void addValue​(char v)
        Adds 1 to the frequency count for v.
        Parameters:
        v - the value to add.

      • clear

        public void clear()
        Clears the frequency table

      • valuesIterator

        public java.util.Iterator<java.lang.Comparable<?>> valuesIterator()
        Returns an Iterator over the set of values that have been added.

        If added values are integral (i.e., integers, longs, Integers, or Longs), they are converted to Longs when they are added, so the objects returned by the Iterator will in this case be Longs.

        Returns:
        values Iterator

      • getSumFreq

        public long getSumFreq()
        Returns the sum of all frequencies.
        Returns:
        the total frequency count.

      • getCount

        @Deprecated
public long getCount​(java.lang.Object v)
        Deprecated.
        replaced by getCount(Comparable) as of 2.0
        Returns the number of values = v. Returns 0 if the value is not comparable.
        Parameters:
        v - the value to lookup.
        Returns:
        the frequency of v.

      • getCount

        public long getCount​(java.lang.Comparable<?> v)
        Returns the number of values = v. Returns 0 if the value is not comparable.
        Parameters:
        v - the value to lookup.
        Returns:
        the frequency of v.

      • getCount

        public long getCount​(int v)
        Returns the number of values = v.
        Parameters:
        v - the value to lookup.
        Returns:
        the frequency of v.

      • getCount

        public long getCount​(long v)
        Returns the number of values = v.
        Parameters:
        v - the value to lookup.
        Returns:
        the frequency of v.

      • getCount

        public long getCount​(char v)
        Returns the number of values = v.
        Parameters:
        v - the value to lookup.
        Returns:
        the frequency of v.

      • getUniqueCount

        public int getUniqueCount()
        Returns the number of values in the frequency table.
        Returns:
        the number of unique values that have been added to the frequency table.
        See Also:
        valuesIterator()

      • getPct

        @Deprecated
public double getPct​(java.lang.Object v)
        Deprecated.
        replaced by getPct(Comparable) as of 2.0
        Returns the percentage of values that are equal to v (as a proportion between 0 and 1).

        Returns Double.NaN if no values have been added.

        Parameters:
        v - the value to lookup
        Returns:
        the proportion of values equal to v

      • getPct

        public double getPct​(java.lang.Comparable<?> v)
        Returns the percentage of values that are equal to v (as a proportion between 0 and 1).

        Returns Double.NaN if no values have been added.

        Parameters:
        v - the value to lookup
        Returns:
        the proportion of values equal to v

      • getPct

        public double getPct​(int v)
        Returns the percentage of values that are equal to v (as a proportion between 0 and 1).
        Parameters:
        v - the value to lookup
        Returns:
        the proportion of values equal to v

      • getPct

        public double getPct​(long v)
        Returns the percentage of values that are equal to v (as a proportion between 0 and 1).
        Parameters:
        v - the value to lookup
        Returns:
        the proportion of values equal to v

      • getPct

        public double getPct​(char v)
        Returns the percentage of values that are equal to v (as a proportion between 0 and 1).
        Parameters:
        v - the value to lookup
        Returns:
        the proportion of values equal to v

      • getCumFreq

        @Deprecated
public long getCumFreq​(java.lang.Object v)
        Deprecated.
        replaced by getCumFreq(Comparable) as of 2.0
        Returns the cumulative frequency of values less than or equal to v.

        Returns 0 if v is not comparable to the values set.

        Parameters:
        v - the value to lookup.
        Returns:
        the proportion of values equal to v

      • getCumFreq

        public long getCumFreq​(java.lang.Comparable<?> v)
        Returns the cumulative frequency of values less than or equal to v.

        Returns 0 if v is not comparable to the values set.

        Parameters:
        v - the value to lookup.
        Returns:
        the proportion of values equal to v

      • getCumFreq

        public long getCumFreq​(int v)
        Returns the cumulative frequency of values less than or equal to v.

        Returns 0 if v is not comparable to the values set.

        Parameters:
        v - the value to lookup
        Returns:
        the proportion of values equal to v

      • getCumFreq

        public long getCumFreq​(long v)
        Returns the cumulative frequency of values less than or equal to v.

        Returns 0 if v is not comparable to the values set.

        Parameters:
        v - the value to lookup
        Returns:
        the proportion of values equal to v

      • getCumFreq

        public long getCumFreq​(char v)
        Returns the cumulative frequency of values less than or equal to v.

        Returns 0 if v is not comparable to the values set.

        Parameters:
        v - the value to lookup
        Returns:
        the proportion of values equal to v

      • getCumPct

        @Deprecated
public double getCumPct​(java.lang.Object v)
        Deprecated.
        replaced by getCumPct(Comparable) as of 2.0
        Returns the cumulative percentage of values less than or equal to v (as a proportion between 0 and 1).

        Returns Double.NaN if no values have been added. Returns 0 if at least one value has been added, but v is not comparable to the values set.

        Parameters:
        v - the value to lookup
        Returns:
        the proportion of values less than or equal to v

      • getCumPct

        public double getCumPct​(java.lang.Comparable<?> v)
        Returns the cumulative percentage of values less than or equal to v (as a proportion between 0 and 1).

        Returns Double.NaN if no values have been added. Returns 0 if at least one value has been added, but v is not comparable to the values set.

        Parameters:
        v - the value to lookup
        Returns:
        the proportion of values less than or equal to v

      • getCumPct

        public double getCumPct​(int v)
        Returns the cumulative percentage of values less than or equal to v (as a proportion between 0 and 1).

        Returns 0 if v is not comparable to the values set.

        Parameters:
        v - the value to lookup
        Returns:
        the proportion of values less than or equal to v

      • getCumPct

        public double getCumPct​(long v)
        Returns the cumulative percentage of values less than or equal to v (as a proportion between 0 and 1).

        Returns 0 if v is not comparable to the values set.

        Parameters:
        v - the value to lookup
        Returns:
        the proportion of values less than or equal to v

      • getCumPct

        public double getCumPct​(char v)
        Returns the cumulative percentage of values less than or equal to v (as a proportion between 0 and 1).

        Returns 0 if v is not comparable to the values set.

        Parameters:
        v - the value to lookup
        Returns:
        the proportion of values less than or equal to v

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object

      • equals

        public boolean equals​(java.lang.Object obj)
        Overrides:
        equals in class java.lang.Object