org.apache.commons.math.stat
Class Frequency

java.lang.Object
  org.apache.commons.math.stat.Frequency

All Implemented Interfaces:

Serializable

public class Frequency

extends Object

implements Serializable

Maintains a frequency distribution.

Accepts int, long, char or Object 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(new Long(2)), addValue(2), addValue(2l) all have the same effect (similarly for arguments to getCount, etc.).

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

Version:

$Revision: 1.29 $ $Date: 2004/09/21 03:02:34 $

See Also:

Serialized Form

Field Summary

(package private) static long

serialVersionUID Serializable version identifier

Constructor Summary

Frequency()
Default constructor.

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

Method Summary

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(Integer v) Adds 1 to the frequency count for v.
void	addValue(long v) Adds 1 to the frequency count for v.
void	addValue(Object v) Adds 1 to the frequency count for v.
void	clear() Clears the frequency table
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(Object v) Returns the number of values = v.
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(Object 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(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(Object v) Returns the cumulative percentage of values less than or equal to v (as a proportion between 0 and 1).
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(Object 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.
String	toString() Return a string representation of this frequency distribution.
Iterator	valuesIterator() Returns an Iterator over the set of values that have been added.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

serialVersionUID

static final long serialVersionUID

Serializable version identifier

See Also:

Constant Field Values

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.

Returns:

a string representation.

addValue

public void addValue(Object v)

Adds 1 to the frequency count for v.

Parameters:

v - the value to add.

Throws:

IllegalArgumentException - if v is not comparable.

addValue

public void addValue(int v)

Adds 1 to the frequency count for v.

Parameters:

v - the value to add.

addValue

public void addValue(Integer v)

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 Iterator valuesIterator()

Returns an Iterator over the set of values that have been added.

If added values are itegral (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

public long getCount(Object v)

Returns the number of values = v.

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.

getPct

public double getPct(Object 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

public long getCumFreq(Object 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(Object 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