JSci.maths.statistics
Class TDistribution

java.lang.Object
  JSci.maths.statistics.ProbabilityDistribution
      JSci.maths.statistics.TDistribution

public final class TDistribution
extends ProbabilityDistribution

The TDistribution class provides an object for encapsulating student's t-distributions.

Constructor Summary

TDistribution(int r)
Constructor for student's t-distribution.

Method Summary

double	cumulative(double X) Cumulative student's t-distribution function.
int	getDegreesOfFreedom() Returns the degrees of freedom.
double	inverse(double probability) Inverse of the cumulative student's t-distribution function.
double	probability(double X) Probability density function of a student's t-distribution.

Methods inherited from class JSci.maths.statistics.ProbabilityDistribution

checkRange, checkRange, findRoot

Methods inherited from class java.lang.Object

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

Constructor Detail

TDistribution

public TDistribution(int r)

Constructor for student's t-distribution.

Parameters:

r - degrees of freedom.

Method Detail

getDegreesOfFreedom

public int getDegreesOfFreedom()

Returns the degrees of freedom.

probability

public double probability(double X)

Probability density function of a student's t-distribution.

Specified by:

probability in class ProbabilityDistribution

Returns:

the probability that a stochastic variable x has the value X, i.e. P(x=X).

cumulative

public double cumulative(double X)

Cumulative student's t-distribution function.

Specified by:

cumulative in class ProbabilityDistribution

Returns:

the probability that a stochastic variable x is less then X, i.e. P(x<X).

inverse

public double inverse(double probability)

Inverse of the cumulative student's t-distribution function.

Specified by:

inverse in class ProbabilityDistribution

Returns:

the value X for which P(x<X).