Frequency (Apache Commons Math 3.6.1 API)

java.lang.Object
- org.apache.commons.math3.stat.Frequency

All Implemented Interfaces:

Serializable
```
public class Frequency
extends Object
implements 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.).

NOTE: byte and short values will be implicitly converted to int values by the compiler, thus there are no explicit overloaded methods for these primitive types.

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.

Float is not coerced to Double. Since they are not Comparable with each other the user must do any necessary coercion. Float.NaN and Double.NaN are not treated specially; they may occur in input and will occur in output if appropriate.
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 and Description

Frequency()
Default constructor.

Frequency(Comparator<?> comparator)
Constructor allowing values Comparator to be specified.

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

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addValue(char v)` Adds 1 to the frequency count for v.
`void`	`addValue(Comparable<?> 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`	`clear()` Clears the frequency table
`Iterator<Map.Entry<Comparable<?>,Long>>`	`entrySetIterator()` Return an Iterator over the set of keys and values that have been added.
`boolean`	`equals(Object obj)`
`long`	`getCount(char v)` Returns the number of values equal to v.
`long`	`getCount(Comparable<?> v)` Returns the number of values equal to v.
`long`	`getCount(int v)` Returns the number of values equal to v.
`long`	`getCount(long v)` Returns the number of values equal to v.
`long`	`getCumFreq(char v)` Returns the cumulative frequency of values less than or equal to v.
`long`	`getCumFreq(Comparable<?> 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.
`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(Comparable<?> 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).
`List<Comparable<?>>`	`getMode()` Returns the mode value(s) in comparator order.
`double`	`getPct(char v)` Returns the percentage of values that are equal to v (as a proportion between 0 and 1).
`double`	`getPct(Comparable<?> 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).
`long`	`getSumFreq()` Returns the sum of all frequencies.
`int`	`getUniqueCount()` Returns the number of values in the frequency table.
`int`	`hashCode()`
`void`	`incrementValue(char v, long increment)` Increments the frequency count for v.
`void`	`incrementValue(Comparable<?> v, long increment)` Increments the frequency count for v.
`void`	`incrementValue(int v, long increment)` Increments the frequency count for v.
`void`	`incrementValue(long v, long increment)` Increments the frequency count for v.
`void`	`merge(Collection<Frequency> others)` Merge a `Collection` of `Frequency` objects into this instance.
`void`	`merge(Frequency other)` Merge another Frequency object's counts into this instance.
`String`	`toString()` Return a string representation of this frequency distribution.
`Iterator<Comparable<?>>`	`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 Detail
  - Frequency
```
public Frequency()
```
    Default constructor.
  - Frequency
```
public Frequency(Comparator<?> comparator)
```
    Constructor allowing values Comparator to be specified.
    
    Parameters:
    comparator - Comparator used to order values
- Method Detail
  - toString
```
public String toString()
```
    Return a string representation of this frequency distribution.
    
    Overrides:
    
    toString in class Object
    
    Returns:
    a string representation.
  - addValue
```
public void addValue(Comparable<?> v)
              throws MathIllegalArgumentException
```
    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:
    
    MathIllegalArgumentException - if v is not comparable with previous entries
  - addValue
```
public void addValue(int v)
              throws MathIllegalArgumentException
```
    Adds 1 to the frequency count for v.
    
    Parameters:
    v - the value to add.
    
    Throws:
    
    MathIllegalArgumentException - if the table contains entries not comparable to Long
  - addValue
```
public void addValue(long v)
              throws MathIllegalArgumentException
```
    Adds 1 to the frequency count for v.
    
    Parameters:
    v - the value to add.
    
    Throws:
    
    MathIllegalArgumentException - if the table contains entries not comparable to Long
  - addValue
```
public void addValue(char v)
              throws MathIllegalArgumentException
```
    Adds 1 to the frequency count for v.
    
    Parameters:
    v - the value to add.
    
    Throws:
    
    MathIllegalArgumentException - if the table contains entries not comparable to Char
  - incrementValue
```
public void incrementValue(Comparable<?> v,
                  long increment)
                    throws MathIllegalArgumentException
```
    Increments 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.
    increment - the amount by which the value should be incremented
    
    Throws:
    
    MathIllegalArgumentException - if v is not comparable with previous entries
    Since:
    
    3.1
  - incrementValue
```
public void incrementValue(int v,
                  long increment)
                    throws MathIllegalArgumentException
```
    Increments 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.
    increment - the amount by which the value should be incremented
    
    Throws:
    
    MathIllegalArgumentException - if the table contains entries not comparable to Long
    Since:
    
    3.3
  - incrementValue
```
public void incrementValue(long v,
                  long increment)
                    throws MathIllegalArgumentException
```
    Increments 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.
    increment - the amount by which the value should be incremented
    
    Throws:
    
    MathIllegalArgumentException - if the table contains entries not comparable to Long
    Since:
    
    3.3
  - incrementValue
```
public void incrementValue(char v,
                  long increment)
                    throws MathIllegalArgumentException
```
    Increments 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.
    increment - the amount by which the value should be incremented
    
    Throws:
    
    MathIllegalArgumentException - if the table contains entries not comparable to Char
    Since:
    
    3.3
  - clear
```
public void clear()
```
    Clears the frequency table
  - valuesIterator
```
public Iterator<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
  - entrySetIterator
```
public Iterator<Map.Entry<Comparable<?>,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.
    If added values are integral (i.e., integers, longs, Integers, or Longs), they are converted to Longs when they are added, so the values of the map entries returned by the Iterator will in this case be Longs.
    
    Returns:
    entry set Iterator
    Since:
    
    3.1
  - getSumFreq
```
public long getSumFreq()
```
    Returns the sum of all frequencies.
    
    Returns:
    the total frequency count.
  - getCount
```
public long getCount(Comparable<?> 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.
  - getCount
```
public long getCount(int v)
```
    Returns the number of values equal to v.
    
    Parameters:
    v - the value to lookup.
    
    Returns:
    the frequency of v.
  - getCount
```
public long getCount(long v)
```
    Returns the number of values equal to v.
    
    Parameters:
    v - the value to lookup.
    
    Returns:
    the frequency of v.
  - getCount
```
public long getCount(char v)
```
    Returns the number of values equal to 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
```
public double getPct(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. 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 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
```
public long getCumFreq(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
```
public double getCumPct(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
  - getMode
```
public List<Comparable<?>> getMode()
```
    Returns the mode value(s) in comparator order.
    
    Returns:
    a list containing the value(s) which appear most often.
    Since:
    
    3.3
  - merge
```
public void merge(Frequency 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
    Since:
    
    3.1
  - merge
```
public void merge(Collection<Frequency> 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
    Since:
    
    3.1
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - equals
```
public boolean equals(Object obj)
```
    Overrides:
    
    equals in class Object

Class Frequency

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Frequency

Frequency

Method Detail

toString

addValue

addValue

addValue

addValue

incrementValue

incrementValue

incrementValue

incrementValue

clear

valuesIterator

entrySetIterator

getSumFreq

getCount

getCount

getCount

getCount

getUniqueCount

getPct

getPct

getPct

getPct

getCumFreq

getCumFreq

getCumFreq

getCumFreq

getCumPct

getCumPct

getCumPct

getCumPct

getMode

merge

merge

hashCode

equals