edu.ucla.stat.SOCR.distributions
Class ErlangDistribution

java.lang.Object
  edu.ucla.stat.SOCR.core.SOCRValueSettable
      edu.ucla.stat.SOCR.core.Distribution
          edu.ucla.stat.SOCR.distributions.ErlangDistribution

All Implemented Interfaces:

IValueSettable, Pluginable, java.util.Observer

public class ErlangDistribution
extends Distribution

A Java implmentation of the Erlang distribution with specified Scale (scale) and shape (shape) parameters http://mathworld.wolfram.com/ErlangDistribution.html .

Field Summary

Fields inherited from class edu.ucla.stat.SOCR.core.Distribution

applet, CONTINUOUS, DISCRETE, MAXMGFXVAL, MAXMGFYVAL, MINMGFXVAL, MIXED, name

Constructor Summary

ErlangDistribution()
Default constructor: creates an Erlang distribution with scale and shape parameters equal to 1

ErlangDistribution(double[] distData)
Constructor: creates an Erlang distribution from a sample data series and estimates the scale (a) and shape (b) parameters.

ErlangDistribution(double a, int b)
Constructor: creates an Erlang distribution with scale (a) and shape (b) parameters.

ErlangDistribution(float[] distData)
Constructor: creates an Erlang distribution from a sample data series and estimates the scale (a) and shape (b) parameters.

Method Summary

double	getCDF(double x) Compute the cumulative distribution function.
double	getDensity(double x) Define the Erlang getDensity function
double	getMaxDensity() Compute the maximum getDensity
double	getMean() Compute the mean in closed form
double	getMGF(double t) Computes the moment generating function in closed form for a parameter t which lies in the domain of the distribution.
double	getMode() Compute the mean in closed form
java.lang.String	getOnlineDescription() This method returns an online description of this distribution.
double	getScale() Get the scale paramter
double	getSD() Compute the variance in closed form
int	getShape() Get the shape parameter
double	getVariance() Compute the variance in closed form
void	initialize() used for some subclass to initialize before being used
void	paramEstimate(double[] distData) Overwrites the method in distribution for estimating parameters
void	setParameters(double a, int b) Set the parameters, compute the normalizing constant NormalizingConst, and specifies the interval and partition.
void	setScale(double a) Sets the scale parameter
void	setShape(int b) Sets the shape parameter
void	valueChanged()

Methods inherited from class edu.ucla.stat.SOCR.core.Distribution

addObserver, betaCDF, comb, factorial, findGFRoot, findRoot, gamma, gammaCDF, getDisplayPane, getDomain, getFailureRate, getGFDerivative, getGFSecondDerivative, getInstance, getLocalHelp, getMean, getMedian, getMgfDomain, getName, getPGF, getPGFDomain, getQuantile, getSampleMoment, getSOCRDistributionFunctors, getSOCRDistributions, getType, getVariance, inverseCDF, logGamma, perm, sampleMean, sampleVar, setApplet, setDomain, setDomain, setMGFDomain, setMGFDomain, setMGFParameters, setMGFParameters, setMGFParameters, setMGFParameters, setParameters, setPGFDomain, setPGFDomain, setPGFParameters, setPGFParameters, setPGFParameters, setPGFParameters, simulate, update, valueChanged

Methods inherited from class edu.ucla.stat.SOCR.core.SOCRValueSettable

createComponentSetter, createValueSetter, createValueSetter, createValueSetter, createValueSetter, getComponentSetter, getComponentSetters, getValueSetter, getValueSetters

Methods inherited from class java.lang.Object

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

Constructor Detail

ErlangDistribution

public ErlangDistribution()

Default constructor: creates an Erlang distribution with scale and shape parameters equal to 1

ErlangDistribution

public ErlangDistribution(double a,
                          int b)

Constructor: creates an Erlang distribution with scale (a) and shape (b) parameters.

ErlangDistribution

public ErlangDistribution(double[] distData)

Constructor: creates an Erlang distribution from a sample data series and estimates the scale (a) and shape (b) parameters.

ErlangDistribution

public ErlangDistribution(float[] distData)

Constructor: creates an Erlang distribution from a sample data series and estimates the scale (a) and shape (b) parameters.

Method Detail

initialize

public void initialize()

Description copied from class: Distribution

used for some subclass to initialize before being used

Overrides:

initialize in class Distribution

valueChanged

public void valueChanged()

Overrides:

valueChanged in class Distribution

setParameters

public void setParameters(double a,
                          int b)

Set the parameters, compute the normalizing constant NormalizingConst, and specifies the interval and partition.

setScale

public void setScale(double a)

Sets the scale parameter

setShape

public void setShape(int b)

Sets the shape parameter

getScale

public double getScale()

Get the scale paramter

getShape

public int getShape()

Get the shape parameter

getDensity

public double getDensity(double x)

Define the Erlang getDensity function

Specified by:

getDensity in class Distribution

getMaxDensity

public double getMaxDensity()

Compute the maximum getDensity

Overrides:

getMaxDensity in class Distribution

getMean

public double getMean()

Compute the mean in closed form

Overrides:

getMean in class Distribution

getMode

public double getMode()

Compute the mean in closed form

paramEstimate

public void paramEstimate(double[] distData)

Overwrites the method in distribution for estimating parameters

Overrides:

paramEstimate in class Distribution

getVariance

public double getVariance()

Compute the variance in closed form

Overrides:

getVariance in class Distribution

getSD

public double getSD()

Compute the variance in closed form

Overrides:

getSD in class Distribution

getCDF

public double getCDF(double x)

Compute the cumulative distribution function.

Overrides:

getCDF in class Distribution

getMGF

public double getMGF(double t)
              throws ParameterOutOfBoundsException

Computes the moment generating function in closed form for a parameter t which lies in the domain of the distribution.

Overrides:

getMGF in class Distribution

Throws:

ParameterOutOfBoundsException

getOnlineDescription

public java.lang.String getOnlineDescription()

This method returns an online description of this distribution.

Overrides:

getOnlineDescription in class Distribution