org.statcato.statistics
Class NormalProbabilityDistribution

java.lang.Object
  extended by org.statcato.statistics.ProbabilityDistribution
      extended by org.statcato.statistics.NormalProbabilityDistribution

public class NormalProbabilityDistribution
extends ProbabilityDistribution

Normal probability distribution class.

Since:
1.0
Version:
%I%, %G%
Author:
Margaret Yau

Constructor Summary
NormalProbabilityDistribution(double mu, double sigma)
          Constructor a normal probability distribution given the mean and standard deviation.
 
Method Summary
 double cumulativeProbability(double x)
          Returns the cumulative probabililty up to x.
 double density(double x)
          Returns the density of the distribution at x.
 double inverseCumulativeProbability(double area)
          Returns the inverse cumulative probability.
 
Methods inherited from class org.statcato.statistics.ProbabilityDistribution
inverseCumulativeProbability
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

NormalProbabilityDistribution

public NormalProbabilityDistribution(double mu,
                                     double sigma)
Constructor a normal probability distribution given the mean and standard deviation.

Parameters:
mu - mean
sigma - standard deviation
Method Detail

density

public double density(double x)
Returns the density of the distribution at x.

Specified by:
density in class ProbabilityDistribution
Parameters:
x -
Returns:
probability density at x

cumulativeProbability

public double cumulativeProbability(double x)
Returns the cumulative probabililty up to x.

Specified by:
cumulativeProbability in class ProbabilityDistribution
Parameters:
x -
Returns:
cumulative probability P(<=x)

inverseCumulativeProbability

public double inverseCumulativeProbability(double area)
Returns the inverse cumulative probability.

Parameters:
area - cumulative probability
Returns:
inverse cumulative probability