jphase
Class Utils

java.lang.Object
  jphase.Utils

public class Utils
extends java.lang.Object

Constructor Summary

Utils()

Method Summary

static double	binomial(int n, int k) Binomial coefficient
static double	distance(double[] v1, double[] v2) Euclidean norm btween given arrays
static double	fact(int n) Factorial function ( n! ).
static double	gammaP(double a, double x) Incomplete gamma function.
static double[][]	initUpperTriangular(int n) Creates storage for un upper triangular matrix.
static double	lnBinomial(int n, int k) ln Binomial coefficient.
static double	lnFactorial(int n) Computes the log of Factorial function
static double	lnGamma(double xx) Computes the log of gamma function.
static double	lnPermut(int n, int k) Computes ln( n!/(n-k)! )
static double	permut(int n, int k) Computes n!/(n-k)!
static double	pow(double x, int n) Power function obtained by multiplying.

Methods inherited from class java.lang.Object

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

Constructor Detail

Utils

public Utils()

Method Detail

lnPermut

public static double lnPermut(int n,
                              int k)

Computes ln( n!/(n-k)! )

Parameters:

n -

k -

Returns:

ln( n!/(n-k) )!

permut

public static double permut(int n,
                            int k)

Computes n!/(n-k)!

Parameters:

n -

k -

Returns:

Computes n!/(n-k)!

lnGamma

public static double lnGamma(double xx)

Computes the log of gamma function.

Parameters:

xx - value

Returns:

lnGamma(xx)

lnFactorial

public static double lnFactorial(int n)

Computes the log of Factorial function

Parameters:

n -

Returns:

ln (n!)

fact

public static double fact(int n)

Factorial function ( n! ).

Parameters:

n -

Returns:

n!

gammaP

public static double gammaP(double a,
                            double x)

Incomplete gamma function. ;

Parameters:

a - argument

x - upper limit

Returns:

integ{0,infty,x} e^(-t) t^a / gamma(a) dt

binomial

public static double binomial(int n,
                              int k)

Binomial coefficient

Parameters:

n -

k -

Returns:

n!/ k! (n-k)!

lnBinomial

public static double lnBinomial(int n,
                                int k)

ln Binomial coefficient.

Parameters:

n -

k -

Returns:

ln [n!/ k! (n-k)!]

pow

public static double pow(double x,
                         int n)

Power function obtained by multiplying.

Parameters:

x -

n -

Returns:

x^n

distance

public static double distance(double[] v1,
                              double[] v2)

Euclidean norm btween given arrays

Parameters:

v1 -

v2 -

Returns:

Euclidean norm

initUpperTriangular

public static double[][] initUpperTriangular(int n)

Creates storage for un upper triangular matrix.

Parameters:

n -

Returns:

An nxn upper triangular matrix.