edu.uah.math.distributions
Class WalkPositionDistribution

java.lang.Object
  edu.uah.math.distributions.Distribution
      edu.uah.math.distributions.WalkPositionDistribution

All Implemented Interfaces:

java.io.Serializable

public class WalkPositionDistribution
extends Distribution
implements java.io.Serializable

This class models the distribution of the position at time n for a random walk on the interval [0, n].

Version:

August, 2003

Author:

Kyle Siegrist, Dawn Duehring

See Also:

Serialized Form

Field Summary

Fields inherited from class edu.uah.math.distributions.Distribution

CONTINUOUS, DISCRETE, MIXED

Constructor Summary

WalkPositionDistribution()
This default constructor creates a new WalkPositionDistribution with time parameter 10 and probability p = 0.5.

WalkPositionDistribution(int n, double p)
This general constructor creates a new distribution with specified time and probability parameters.

Method Summary

double	getDensity(double x) This method computes the density function.
double	getMaxDensity() This method returns the maximum value of the density function.
double	getMean() This method computes the mean.
double	getProbability() This method returns the probability parameter.
double	getSteps() This method returns the number of steps in the random walk.
double	getVariance() This method computes the variance.
void	setParameters(int n, double p) This method sets the time and probability parameters.
void	setProbability(double p) This method sets the probability parameter.
void	setSteps(int n) This method sets the number of steps.
double	simulate() This method simulates a value from the distribution.
java.lang.String	toString() This method returns a string that gives the name of the distribution and the values of the parameters.

Methods inherited from class edu.uah.math.distributions.Distribution

getCDF, getDomain, getFailureRate, getMedian, getMGF, getMoment, getMoment, getPGF, getQuantile, getSD, getType, setDomain, setDomain

Methods inherited from class java.lang.Object

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

Constructor Detail

WalkPositionDistribution

public WalkPositionDistribution(int n,
                                double p)

This general constructor creates a new distribution with specified time and probability parameters.

Parameters:

n - the number of steps

p - the probabiltiy of a step in the positive direction

WalkPositionDistribution

public WalkPositionDistribution()

This default constructor creates a new WalkPositionDistribution with time parameter 10 and probability p = 0.5.

Method Detail

setParameters

public void setParameters(int n,
                          double p)

This method sets the time and probability parameters.

Parameters:

n - the number of steps

p - the probability of a step in the positive direction

getDensity

public double getDensity(double x)

This method computes the density function.

Specified by:

getDensity in class Distribution

Parameters:

x - a number in the domain of the distribution

Returns:

the probability density at x

getMaxDensity

public double getMaxDensity()

This method returns the maximum value of the density function.

Overrides:

getMaxDensity in class Distribution

Returns:

the maximum value of the probability density function

getMean

public double getMean()

This method computes the mean.

Overrides:

getMean in class Distribution

Returns:

the mean of the distribution

getVariance

public double getVariance()

This method computes the variance.

Overrides:

getVariance in class Distribution

Returns:

the variance of the distribution

setSteps

public void setSteps(int n)

This method sets the number of steps.

Parameters:

n - the number of steps

getSteps

public double getSteps()

This method returns the number of steps in the random walk.

Returns:

the number of steps

setProbability

public void setProbability(double p)

This method sets the probability parameter.

Parameters:

p - the probability of a step in the positve direciton

getProbability

public double getProbability()

This method returns the probability parameter.

Returns:

the probability of a step in the positive direction.

simulate

public double simulate()

This method simulates a value from the distribution.

Overrides:

simulate in class Distribution

Returns:

a simulated value from the distribution

toString

public java.lang.String toString()

This method returns a string that gives the name of the distribution and the values of the parameters.

Overrides:

toString in class Distribution

Returns:

a string giving the name of the distribution and the values of the parameters