org.jscience.physics.nuclear.kinematics.math.statistics
Class MathUtils

java.lang.Object
  org.jscience.physics.nuclear.kinematics.math.statistics.MathUtils

public class MathUtils
extends java.lang.Object

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Constructor Summary

MathUtils()
Creates a new MathUtils object.

Method Summary

static double	ave(double[] data) DOCUMENT ME!
static double	betai(double a, double b, double x) Incomplete beta function.
static double	calculateStudentsT(double tObserved, double dof) Returns the probability that the absolute value of a t-statistic would be smaller than tObserved, for a t-distribution with dof degrees of freedom and a mean of zero.
static double	findOneSigmaT(int dof) Calculates t-statistic such that calculateStudentsT(findOneSigmaT(dof),dof) returns 0.683, the one-sigma probability for the normal distribution.
static double	gammln(double xx) Returns Incomplete gamma P(a,x) evaluated by series.
static double	gammq(double a, double x) Returns the incomplete gamma function Q(a,x) == 1 - P(a,x).
static double	gcf(double a, double x) Returns Incomplete gamma Q(a,x) evaluated by series.
static double	gser(double a, double x)
static void	main(java.lang.String[] args) DOCUMENT ME!
static double	var(double[] data) DOCUMENT ME!
double[]	zbrac(Function func, double x1, double x2) From zbrac.c in "Numerical Recipes".
static double	zbrent(Function func, double x1, double x2, double tol) From zbrent.c in "Numerical Recipes".

Methods inherited from class java.lang.Object

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

Constructor Detail

MathUtils

public MathUtils()

Creates a new MathUtils object.

Method Detail

ave

public static double ave(double[] data)

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Parameters:

data - DOCUMENT ME!

Returns:

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var

public static double var(double[] data)

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Parameters:

data - DOCUMENT ME!

Returns:

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gammq

public static double gammq(double a,
                           double x)
                    throws StatisticsException

Returns the incomplete gamma function Q(a,x) == 1 - P(a,x). P(x) == 1/gamma(a)Intgegrate[exp[-t]t(a-1),{t,0,x}] ; (a>0)

Parameters:

a - DOCUMENT ME!

x - DOCUMENT ME!

Returns:

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Throws:

StatisticsException - DOCUMENT ME!

gser

public static double gser(double a,
                          double x)
                   throws StatisticsException

Parameters:

a - DOCUMENT ME!

x - DOCUMENT ME!

Returns:

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Throws:

StatisticsException - DOCUMENT ME!

gammln

public static double gammln(double xx)

Returns Incomplete gamma P(a,x) evaluated by series.

Parameters:

xx - DOCUMENT ME!

Returns:

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gcf

public static double gcf(double a,
                         double x)
                  throws StatisticsException

Returns Incomplete gamma Q(a,x) evaluated by series.

Parameters:

a - DOCUMENT ME!

x - DOCUMENT ME!

Returns:

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Throws:

StatisticsException - DOCUMENT ME!

zbrac

public double[] zbrac(Function func,
                      double x1,
                      double x2)
               throws StatisticsException

From zbrac.c in "Numerical Recipes". Given a Function and initial guessed range x1 to x2, the method expands the range geometrically until a root is bracketed by the values in the returned array. If the range becomes unacceptably large, and exception is thrown, and no bracketing values ever get returned.

Parameters:

func - DOCUMENT ME!

x1 - DOCUMENT ME!

x2 - DOCUMENT ME!

Returns:

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Throws:

StatisticsException - DOCUMENT ME!

zbrent

public static double zbrent(Function func,
                            double x1,
                            double x2,
                            double tol)
                     throws StatisticsException

From zbrent.c in "Numerical Recipes". Using Brent's method, finds the root of Function func known to lie between x1 and x2. The root is returned, and will be refined until it's accuracy is tol.

Parameters:

func - DOCUMENT ME!

x1 - DOCUMENT ME!

x2 - DOCUMENT ME!

tol - DOCUMENT ME!

Returns:

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Throws:

StatisticsException - DOCUMENT ME!

betai

public static double betai(double a,
                           double b,
                           double x)
                    throws StatisticsException

Incomplete beta function. Used to calculate Student's T.

Parameters:

a - DOCUMENT ME!

b - DOCUMENT ME!

x - DOCUMENT ME!

Returns:

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Throws:

StatisticsException - DOCUMENT ME!

calculateStudentsT

public static double calculateStudentsT(double tObserved,
                                        double dof)
                                 throws StatisticsException

Returns the probability that the absolute value of a t-statistic would be smaller than tObserved, for a t-distribution with dof degrees of freedom and a mean of zero.

Parameters:

tObserved - DOCUMENT ME!

dof - DOCUMENT ME!

Returns:

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Throws:

StatisticsException - DOCUMENT ME!

findOneSigmaT

public static double findOneSigmaT(int dof)
                            throws StatisticsException

Calculates t-statistic such that calculateStudentsT(findOneSigmaT(dof),dof) returns 0.683, the one-sigma probability for the normal distribution.

Parameters:

dof - DOCUMENT ME!

Returns:

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Throws:

StatisticsException - DOCUMENT ME!

main

public static void main(java.lang.String[] args)

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Parameters:

args - DOCUMENT ME!