org.apache.commons.math.stat

Class Frequency

java.lang.Object

org.apache.commons.math.stat.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 and Description
Frequency() Default constructor.
Frequency(java.util.Comparator<?> comparator) Constructor allowing values Comparator to be specified.

Method Summary

Modifier and Type	Method and Description
void	addValue(char 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(int 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(long v) Adds 1 to the frequency count for v.
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(java.lang.Comparable<?> 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.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(java.lang.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.
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(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(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.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(java.lang.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).
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