sdsu.algorithms.data
Class Geometric

java.lang.Object
  |
  +--sdsu.algorithms.data.ProbabilityDistribution
        |
        +--sdsu.algorithms.data.DiscreteProbability
              |
              +--sdsu.algorithms.data.Bernoulli
                    |
                    +--sdsu.algorithms.data.Geometric

public class Geometric

extends Bernoulli

The Geometric distribution deals with Bernoulli like situations: the sample space is divided into success events and failure events. The geometric distributions answers questions about how many trials are required to get a successful event. The density function maps an integer N to the probability that it requires N trials to get the first success. The nextElement() returns the number of trials needed to get a success in a sequence of random trials. This class is adapted from Smalltalk-80: The language and Its Implementation, Goldberg & Robson, Addison-Wesley, 1983, chapter 21, pages 417-438.

Version:

1.0 10 June 1997

Author:

Roger Whitney (whitney@cs.sdsu.edu)

Constructor Summary

Geometric(double successProbability)
Returns a Geometric.

Method Summary

double	density(double numberOfTrials) Returns the probability that it takes numberOfTrials to get the first successful event.
double	mean() Returns the mean of the distribution
double	variance() Returns the variance of the distribution

Methods inherited from class sdsu.algorithms.data.Bernoulli

nextElement

Methods inherited from class sdsu.algorithms.data.DiscreteProbability

distribution

Methods inherited from class sdsu.algorithms.data.ProbabilityDistribution

density

Methods inherited from class java.lang.Object

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

Constructor Detail

Geometric

public Geometric(double successProbability)
          throws OutOfBoundsException

Returns a Geometric.

Parameters:

successProbability - the probability of a successful event.

Throws:

OutOfBoundsException - thrown if successProbability is not in the interval [0, 1].

Method Detail

density

public double density(double numberOfTrials)
               throws OutOfBoundsException

Returns the probability that it takes numberOfTrials to get the first successful event.

Parameters:

numberOfTrials - an integer number of trials. Will be converted to an int. Must be greater than 0.

Overrides:

density in class Bernoulli

mean

public double mean()

Returns the mean of the distribution

Overrides:

mean in class Bernoulli

variance

public double variance()

Returns the variance of the distribution

Overrides:

variance in class Bernoulli