Package org.hipparchus.stat

Class Frequency<T extends Comparable<T>>

java.lang.Object
org.hipparchus.stat.Frequency<T>
Type Parameters:
T - the element type
All Implemented Interfaces:
Serializable
Direct Known Subclasses:
LongFrequency
public class Frequency<T extends Comparable<T>> extends Object implements Serializable
Maintains a frequency distribution of Comparable values.

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

See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    Frequency()
    Default constructor.
    Frequency(Comparator<? super T> comparator)
    Constructor allowing values Comparator to be specified.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    addValue(T v)
    Adds 1 to the frequency count for v.
    void
    clear()
    Clears the frequency table
    Iterator<Map.Entry<T,Long>>
    entrySetIterator()
    Return an Iterator over the set of keys and values that have been added.
    boolean
    equals(Object obj)
    long
    getCount(T v)
    Returns the number of values equal to v.
    long
    getCumFreq(T v)
    Returns the cumulative frequency of values less than or equal to v.
    double
    getCumPct(T v)
    Returns the cumulative percentage of values less than or equal to v (as a proportion between 0 and 1).
    List<T>
    getMode()
    Returns the mode value(s) in comparator order.
    double
    getPct(T v)
    Returns the percentage of values that are equal to v (as a proportion between 0 and 1).
    long
    getSumFreq()
    Returns the sum of all frequencies.
    int
    getUniqueCount()
    Returns the number of values in the frequency table.
    int
    hashCode()
    void
    incrementValue(T v, long increment)
    Increments the frequency count for v.
    void
    merge(Collection<? extends Frequency<? extends T>> others)
    Merge a Collection of Frequency objects into this instance.
    void
    merge(Frequency<? extends T> other)
    Merge another Frequency object's counts into this instance.
    String
    toString()
    Return a string representation of this frequency distribution.
    Iterator<T>
    valuesIterator()
    Returns an Iterator over the set of values that have been added.

    Methods inherited from class java.lang.Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

  • Constructor Details

    • Frequency

      public Frequency()
      Default constructor.

    • Frequency

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

  • Method Details

    • addValue

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

    • incrementValue

      public void incrementValue(T v, long increment)
      Increments the frequency count for v.
      Parameters:
      v - the value to add.
      increment - the amount by which the value should be incremented

    • clear

      public void clear()
      Clears the frequency table

    • valuesIterator

      public Iterator<T> valuesIterator()
      Returns an Iterator over the set of values that have been added.
      Returns:
      values Iterator

    • entrySetIterator

      public Iterator<Map.Entry<T,Long>> entrySetIterator()
      Return an Iterator over the set of keys and values that have been added. Using the entry set to iterate is more efficient in the case where you need to access respective counts as well as values, since it doesn't require a "get" for every key...the value is provided in the Map.Entry.
      Returns:
      entry set Iterator

    • getSumFreq

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

    • getCount

      public long getCount(T v)
      Returns the number of values equal to v. Returns 0 if the value is not comparable.
      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:

    • getPct

      public double getPct(T 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

    • getCumFreq

      public long getCumFreq(T v)
      Returns the cumulative frequency of values less than or equal to v.
      Parameters:
      v - the value to lookup.
      Returns:
      the proportion of values equal to v

    • getCumPct

      public double getCumPct(T 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.

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

    • getMode

      public List<T> getMode()
      Returns the mode value(s) in comparator order.
      Returns:
      a list containing the value(s) which appear most often.

    • merge

      public void merge(Frequency<? extends T> other) throws NullArgumentException
      Merge another Frequency object's counts into this instance. This Frequency's counts will be incremented (or set when not already set) by the counts represented by other.
      Parameters:
      other - the other Frequency object to be merged
      Throws:
      NullArgumentException - if other is null

    • merge

      public void merge(Collection<? extends Frequency<? extends T>> others) throws NullArgumentException
      Merge a Collection of Frequency objects into this instance. This Frequency's counts will be incremented (or set when not already set) by the counts represented by each of the others.
      Parameters:
      others - the other Frequency objects to be merged
      Throws:
      NullArgumentException - if the collection is null

    • toString

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

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object