org.ojalgo.random

Class Poisson

java.lang.Object

java.lang.Number

org.ojalgo.random.RandomNumber

org.ojalgo.random.Poisson

All Implemented Interfaces:

Serializable, DoubleSupplier, Supplier<Double>, BasicFunction<Double>, NullaryFunction<Double>, DiscreteDistribution, Distribution

public class Poisson
extends RandomNumber

The Poisson distribution is a discrete probability distribution that expresses the probability of a given number of events occurring in a fixed interval of time and/or space if these events occur with a known average rate and independently of the time since the last event. (The Poisson distribution can also be used for the number of events in other specified intervals such as distance, area or volume.) Distribution of number of points in random point process under certain simple assumptions. Approximation to the binomial distribution when aCount is large and aProbability is small. aLambda = aCount * aProbability.

Author:

apete

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.ojalgo.function.BasicFunction

BasicFunction.Differentiable<N extends Number,F extends BasicFunction<N>>, BasicFunction.Integratable<N extends Number,F extends BasicFunction<N>>

Constructor Summary

Constructors

Constructor and Description
Poisson()
Poisson(double aLambda)

Method Summary

Modifier and Type	Method and Description
protected double	generate()
double	getExpected()
double	getProbability(int value) Probability density function
double	getVariance() Subclasses must override either getStandardDeviation() or getVariance()!

Methods inherited from class org.ojalgo.random.RandomNumber

checkProbabilty, doubleValue, floatValue, getStandardDeviation, intValue, invoke, longValue, random, setSeed, toString

Methods inherited from class java.lang.Number

byteValue, shortValue

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.ojalgo.random.Distribution

getStandardDeviation

Methods inherited from interface org.ojalgo.function.NullaryFunction

andThen, get, getAsDouble

Constructor Detail

Poisson

public Poisson()

Poisson

public Poisson(double aLambda)

Method Detail

getExpected

public double getExpected()

getProbability

public double getProbability(int value)

Description copied from interface: DiscreteDistribution

Probability density function

getVariance

public double getVariance()

Description copied from class: RandomNumber

Subclasses must override either getStandardDeviation() or getVariance()!

Specified by:

getVariance in interface Distribution

Overrides:

getVariance in class RandomNumber

See Also:

Distribution.getStandardDeviation(), Distribution.getVariance()

generate

protected double generate()

Specified by:

generate in class RandomNumber