jhplot.math.num.pdf

Class Binomial

java.lang.Object

jhplot.math.num.pdf.DiscreteDistribution

jhplot.math.num.pdf.Binomial

All Implemented Interfaces:

Distribution

public class Binomial
extends DiscreteDistribution

The Binomial distribution.

References:

1. Eric W. Weisstein. "Binomial Distribution." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/Binomial.html

Since:

1.2

Constructor Summary

Constructors

Constructor and Description
Binomial() Default constructor.
Binomial(int n, double p) Create a distribution with the given number of trials and probability of success.

Method Summary

Modifier and Type	Method and Description
double	cumulativeProbability(int x) The CDF for this distribution.
int	getNumberOfTrials() Access the number of trials.
double	getProbabilityOfSuccess() Access probability of success.
int	inverseCumulativeProbability(double p) The inverse CDF for this distribution.
double	probability(int x) The PMF for this distribution.
void	setNumberOfTrials(int n) Modify the number of trials.
void	setProbabilityOfSuccess(double p) Modify probability of success.

Methods inherited from class java.lang.Object

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

Constructor Detail

Binomial

public Binomial()

Default constructor. Number of trials is set to one and probability of success is set to 0.5.

Binomial

public Binomial(int n,
                double p)

Create a distribution with the given number of trials and probability of success.

Parameters:

n - the number of trials.

p - the probability of success.

Method Detail

cumulativeProbability

public double cumulativeProbability(int x)
                             throws NumericException

The CDF for this distribution. This method returns P(X ≤ x).

Specified by:

cumulativeProbability in class DiscreteDistribution

Parameters:

x - the value at which the CDF is evaluated.

Returns:

CDF for this distribution.

Throws:

NumericException - if the cumulative probability can not be computed.

getNumberOfTrials

public int getNumberOfTrials()

Access the number of trials.

Returns:

the number of trials.

getProbabilityOfSuccess

public double getProbabilityOfSuccess()

Access probability of success.

Returns:

the probability of success.

inverseCumulativeProbability

public int inverseCumulativeProbability(double p)
                                 throws NumericException

The inverse CDF for this distribution. This method returns the largest x such that, P(X ≤ x) ≤ p. The return value must also satisfy P(X ≥ x) &ge 1 - p.

Specified by:

inverseCumulativeProbability in class DiscreteDistribution

Parameters:

p - the cumulative probability.

Returns:

x

Throws:

NumericException - if the inverse cumulative probability can not be computed.

probability

public double probability(int x)

The PMF for this distribution. This method returns P(X = x).

Specified by:

probability in class DiscreteDistribution

Parameters:

x - the value at which the probability is evaluated.

Returns:

PMF for this distribution.

setNumberOfTrials

public void setNumberOfTrials(int n)

Modify the number of trials.

Parameters:

n - the new number of trials value.

setProbabilityOfSuccess

public void setProbabilityOfSuccess(double p)

Modify probability of success.

Parameters:

p - the new probability of success value.