com.badlogic.gdx.math

Class CumulativeDistribution<T>

java.lang.Object

com.badlogic.gdx.math.CumulativeDistribution<T>

public class CumulativeDistribution<T>
extends Object

This class represents a cumulative distribution. It can be used in scenarios where there are values with different probabilities and it's required to pick one of those respecting the probability. For example one could represent the frequency of the alphabet letters using a cumulative distribution and use it to randomly pick a letter respecting their probabilities (useful when generating random words). Another example could be point generation on a mesh surface: one could generate a cumulative distribution using triangles areas as interval size, in this way triangles with a large area will be picked more often than triangles with a smaller one. See Wikipedia for a detailed explanation.

Author:

Inferno

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	CumulativeDistribution.CumulativeValue

Constructor Summary

Constructors

Constructor and Description
CumulativeDistribution()

Method Summary

Methods

Modifier and Type	Method and Description
void	add(T value) Adds a value with interval size equal to zero to the distribution
void	add(T value, float intervalSize) Adds a value with a given interval size to the distribution
void	clear() Removes all the values from the distribution
void	generate() Generate the cumulative distribution
void	generateNormalized() Generate the cumulative distribution in [0,1] where each interval will get a frequency between [0,1]
void	generateUniform() Generate the cumulative distribution in [0,1] where each value will have the same frequency and interval size
float	getInterval(int index)
T	getValue(int index)
void	setInterval(int index, float intervalSize) Sets the interval size for the value at the given index
void	setInterval(T obj, float intervalSize) Set the interval size on the passed in object.
int	size()
T	value()
T	value(float probability) Finds the value whose interval contains the given probability Binary search algorithm is used to find the value.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CumulativeDistribution

public CumulativeDistribution()

Method Detail

add

public void add(T value,
       float intervalSize)

Adds a value with a given interval size to the distribution

add

public void add(T value)

Adds a value with interval size equal to zero to the distribution

generate

public void generate()

Generate the cumulative distribution

generateNormalized

public void generateNormalized()

Generate the cumulative distribution in [0,1] where each interval will get a frequency between [0,1]

generateUniform

public void generateUniform()

Generate the cumulative distribution in [0,1] where each value will have the same frequency and interval size

value

public T value(float probability)

Finds the value whose interval contains the given probability Binary search algorithm is used to find the value.

Parameters:

probability -

Returns:

the value whose interval contains the probability

value

public T value()

Returns:

the value whose interval contains a random probability in [0,1]

size

public int size()

Returns:

the amount of values

getInterval

public float getInterval(int index)

Returns:

the interval size for the value at the given position

getValue

public T getValue(int index)

Returns:

the value at the given position

setInterval

public void setInterval(T obj,
               float intervalSize)

Set the interval size on the passed in object. The object must be present in the distribution.

setInterval

public void setInterval(int index,
               float intervalSize)

Sets the interval size for the value at the given index

clear

public void clear()

Removes all the values from the distribution