broadwick.statistics.distributions

Class IntegerDistribution

java.lang.Object

broadwick.statistics.distributions.IntegerDistribution

All Implemented Interfaces:

Serializable

public class IntegerDistribution
extends Object
implements Serializable

A simple class for defining custom distributions. This is, in effect, a histogram.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
private ConcurrentMap<Integer,Integer>	bins
private static RNG	GENERATOR

Constructor Summary

Constructors

Constructor and Description
IntegerDistribution() Create an empty distribution.
IntegerDistribution(int nbins) Create the distribution with a specified number of bins.

Method Summary

Modifier and Type	Method and Description
void	add(IntegerDistribution hist) Adds the content of the argument to the current object.
void	clear() Clear all the data from the distribution, after this method the distribution has no denominator or frequency.
IntegerDistribution	copy() Creates a copy of this histogram and returns it.
Collection<Integer>	getBinContents() Get a collection of the values held in the histogram.
Collection<Integer>	getBins() Get the bins in the histogram.
Integer	getData(Integer bin) Deprecated. use getFrequency() instead
Integer	getFrequency(Integer bin) Get the size of the histogram at the given bin.
int	getNumBins() Get the number of bins.
Integer	getRandomBin() Select a random bin from the cumulative distribution of the histograms contents.
Integer	getRandomBinFrequency() Select a random bin from the cumulative distribution of the frequencies and return the frequency.
Integer	getSumCounts() Get the sum of the counts in the histogram.
private void	init(int nbins) Add a number of entries (keys) to the histogram (with zero value).
IntegerDistribution	normaliseBins(int constant) Normalise the frequency distribution.
void	reset() Resets the value in each bin.
void	reset(int val) Resets the value in each bin.
IntegerDistribution	scaleBins(double factor) Scale the values in the histogram by a given factor.
void	setData(Integer bin) Deprecated. use getFrequency() instead
void	setData(Integer bin, Integer data) Deprecated. use setFrequency() instead
void	setFrequency(Integer bin) Increment the size of a bin.
void	setFrequency(Integer bin, Integer data) Set the value of a bin.
int	size() Get the size (the number of bins) in the histogram.
int[]	toArray() Get an array of the bin values.
String	toCsv() Get a string representation of the histogram in a csv format.
long[]	toLongArray() Get an array of the bin values.
String	toString() Get a string representation of the histogram.

Methods inherited from class java.lang.Object

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

Field Detail

bins

private ConcurrentMap<Integer,Integer> bins

GENERATOR

private static final RNG GENERATOR

Constructor Detail

IntegerDistribution

public IntegerDistribution()

Create an empty distribution.

IntegerDistribution

public IntegerDistribution(int nbins)

Create the distribution with a specified number of bins.

Parameters:

nbins - the number of bins

Method Detail

init

private void init(int nbins)

Add a number of entries (keys) to the histogram (with zero value).

Parameters:

nbins - the number of bins to add.

clear

public void clear()

Clear all the data from the distribution, after this method the distribution has no denominator or frequency.

reset

public final void reset(int val)

Resets the value in each bin.

Parameters:

val - the reset value.

reset

public final void reset()

Resets the value in each bin.

add

public final void add(IntegerDistribution hist)

Adds the content of the argument to the current object.

Parameters:

hist - the histogram data to add.

getNumBins

public final int getNumBins()

Get the number of bins.

Returns:

the number of bins.

setFrequency

public final void setFrequency(Integer bin)

Increment the size of a bin.

Parameters:

bin - the bin to increment.

setFrequency

public final void setFrequency(Integer bin,
                               Integer data)

Set the value of a bin.

Parameters:

bin - the bin.

data - the data.

getFrequency

public final Integer getFrequency(Integer bin)

Get the size of the histogram at the given bin.

Parameters:

bin - the bin.

Returns:

the size of the bin, or null if the bin is not in the histogram.

setData

public final void setData(Integer bin)

Deprecated. use getFrequency() instead

Increment the size of a bin.

Parameters:

bin - the bin to increment.

setData

public final void setData(Integer bin,
                          Integer data)

Deprecated. use setFrequency() instead

Set the value of a bin.

Parameters:

bin - the bin.

data - the data.

getData

public final Integer getData(Integer bin)

Deprecated. use getFrequency() instead

Get the size of the histogram at the given bin.

Parameters:

bin - the bin.

Returns:

the size of the bin, or null if the bin is not in the histogram.

getRandomBin

public final Integer getRandomBin()

Select a random bin from the cumulative distribution of the histograms contents.

Returns:

the index of the random bin, or zero if no bin could be selected.

getRandomBinFrequency

public final Integer getRandomBinFrequency()

Select a random bin from the cumulative distribution of the frequencies and return the frequency.

Returns:

the contents of the randomly selected bin.

copy

public final IntegerDistribution copy()

Creates a copy of this histogram and returns it. The returned IntegerDistribution is a completely different object.

Returns:

a copy of this histogram.

getSumCounts

public final Integer getSumCounts()

Get the sum of the counts in the histogram.

Returns:

the sum of all the bins in the histogram.

getBins

public final Collection<Integer> getBins()

Get the bins in the histogram. The bins are the keySet of the underlying map object.

Returns:

the number of bins.

getBinContents

public final Collection<Integer> getBinContents()

Get a collection of the values held in the histogram. The bins are the keySet of the underlying map object, the values are the contents if the bin.

Returns:

a collection of the values held in the histogram.

size

public final int size()

Get the size (the number of bins) in the histogram.

Returns:

the size

toArray

public final int[] toArray()

Get an array of the bin values.

Returns:

an array of int values.

toLongArray

public final long[] toLongArray()

Get an array of the bin values.

Returns:

an array of long values.

scaleBins

public final IntegerDistribution scaleBins(double factor)

Scale the values in the histogram by a given factor. A copy of the histogram is returned, the original is not modified.

Parameters:

factor - the value by which every value in the hiistogram will be multiplied.

Returns:

the scaled histogram.

normaliseBins

public final IntegerDistribution normaliseBins(int constant)

Normalise the frequency distribution. The returned histogram is a scaled copy of the input histogram so that the sum of the returned histogram is equal to the normalising factor.

Parameters:

constant - the normalising constant

Returns:

the scaled and normalised histogram.

toString

public final String toString()

Get a string representation of the histogram.

Overrides:

toString in class Object

Returns:

the string.

toCsv

public final String toCsv()

Get a string representation of the histogram in a csv format.

Returns:

the string.