jv.vecmath
Class PuMath

java.lang.Object
  jv.vecmath.PuMath

public class PuMath

extends java.lang.Object

Mathematical utility functions extending java.lang.Math.

See Also:

Math

Field Summary

static double	EPS Numerical machine accuracy, e.g. used to check for zero and as stopping criterium.
static double	GOLD Ratio of the golden section GOLD = 2/(sqrt(5)-1).

Constructor Summary

PuMath()

Method Summary

static double	acosh(double x) Mathematical acosh(x)=ln(x+sqrt(x*x-1)) function.
static double	acoth(double x) Mathematical acoth(x) = ln((1.
static boolean	angle(double[] agl, double a, double b, double c) Return all three angles opposite to sides of triangle with given side lengths.
static double	angle(double a, double b, double c) Return angle opposite to side a of triangle with given side lengths.
static double	area(double a, double b, double c) Return area of triangle with given side lengths.
static double	asinh(double x) Mathematical asinh(x)=ln(x+sqrt(x*x+1)) function.
static double	atanh(double x) Mathematical atanh(x) = ln((1.
static double	binom(int n, int k) Return binomial coefficients n over k.
static double	cosh(double x) Mathematical cosh(x) function.
static double	coth(double x) Mathematical coth(x) function.
static void	ctg(double[] ctg, double a, double b, double c) Return cot() of all three angles opposite to sides of triangle with given side lengths.
static double	ctg(double a, double b, double c) Return cot(alpha) of angle opposite to side a of triangle with given side lengths.
static double	dist(double[] v, double[] w) Return distance between two vectors given as double arrays.
static double	dot(double[] v, double[] w) Return dot product of two vectors given as double arrays.
static int	factorial(int n) Return faculty n!
static int	gcd(int m, int n) Compute the greatest common divisor of two integers m and n.
static void	heapsort(int n, double[] arrin, int[] indx) Sort an array of double value in ascending order.
static void	heapsort(int n, int[] arrin, int[] indx) Sort an array of integer value in ascending order.
static double	log(double basis, double arg) Return logarithm with respect to given basis.
static void	main(java.lang.String[] args) Main method to test heapsort method
static double	precision(double x, double p) Rounds the given number to a certain precision.
static void	projectOnto(double[] v, double[] dir) Project vector v onto line dir and store result in v.
static int	sign(double x) Return sign of argument as integer value.
static double	sign(double a, double b) Return first argument with sign of second argument.
static double	sinh(double x) Mathematical sinh(x) function.
static double	sqrDist(double[] v, double[] w) Return square distance between two vectors given as double arrays.
static double	tanh(double x) Mathematical tanh(x) function.
static double	toDegrees(double angrad) Converts an angle measured in radians [0,2Pi] to the equivalent angle measured in degrees [0,360].
static double	toRadians(double angdeg) Converts an angle measured in degrees [0,360] to the equivalent angle measured in radians [0,2Pi].

Methods inherited from class java.lang.Object

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

Field Detail

EPS

public static final double EPS

Numerical machine accuracy, e.g. used to check for zero and as stopping criterium.

See Also:

Constant Field Values

GOLD

public static final double GOLD

Ratio of the golden section GOLD = 2/(sqrt(5)-1).

See Also:

Constant Field Values

Constructor Detail

PuMath

public PuMath()

Method Detail

sign

public static int sign(double x)

Return sign of argument as integer value.

sign

public static double sign(double a,
                          double b)

Return first argument with sign of second argument.

log

public static double log(double basis,
                         double arg)

Return logarithm with respect to given basis. Basis must be larger than 1.

sinh

public static double sinh(double x)

Mathematical sinh(x) function.

cosh

public static double cosh(double x)

Mathematical cosh(x) function.

tanh

public static double tanh(double x)

Mathematical tanh(x) function.

coth

public static double coth(double x)

Mathematical coth(x) function.

asinh

public static double asinh(double x)

Mathematical asinh(x)=ln(x+sqrt(x*x+1)) function.

acosh

public static double acosh(double x)

Mathematical acosh(x)=ln(x+sqrt(x*x-1)) function.

atanh

public static double atanh(double x)

Mathematical atanh(x) = ln((1.+x)/(1.-x))/2. function.

acoth

public static double acoth(double x)

Mathematical acoth(x) = ln((1.+x)/(x-1.))/2. function.

area

public static double area(double a,
                          double b,
                          double c)

Return area of triangle with given side lengths.

angle

public static double angle(double a,
                           double b,
                           double c)

Return angle opposite to side a of triangle with given side lengths.

angle

public static boolean angle(double[] agl,
                            double a,
                            double b,
                            double c)

Return all three angles opposite to sides of triangle with given side lengths.

ctg

public static double ctg(double a,
                         double b,
                         double c)

Return cot(alpha) of angle opposite to side a of triangle with given side lengths.

ctg

public static void ctg(double[] ctg,
                       double a,
                       double b,
                       double c)

Return cot() of all three angles opposite to sides of triangle with given side lengths.

projectOnto

public static void projectOnto(double[] v,
                               double[] dir)

Project vector v onto line dir and store result in v. Both vectors given as double arrays.

dot

public static double dot(double[] v,
                         double[] w)

Return dot product of two vectors given as double arrays.

sqrDist

public static double sqrDist(double[] v,
                             double[] w)

Return square distance between two vectors given as double arrays.

dist

public static double dist(double[] v,
                          double[] w)

Return distance between two vectors given as double arrays.

factorial

public static int factorial(int n)

Return faculty n! for integer argument n.

binom

public static double binom(int n,
                           int k)

Return binomial coefficients n over k.

toRadians

public static double toRadians(double angdeg)

Converts an angle measured in degrees [0,360] to the equivalent angle measured in radians [0,2Pi].

Parameters:

angdeg - an angle, in degrees

Returns:

angle angdeg converted to radians.

Since:

JavaView 3.84.025

toDegrees

public static double toDegrees(double angrad)

Converts an angle measured in radians [0,2Pi] to the equivalent angle measured in degrees [0,360].

Parameters:

angrad - an angle, in radians

Returns:

angle angrad converted to degrees.

Since:

JavaView 3.84.025

gcd

public static int gcd(int m,
                      int n)

Compute the greatest common divisor of two integers m and n.

main

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

Main method to test heapsort method

heapsort

public static final void heapsort(int n,
                                  double[] arrin,
                                  int[] indx)

Sort an array of double value in ascending order. The ascending order of the double array is provided through the indx vector. After performing this method, the indx vector contains the ordering of the double array, i.e. arrin[indx[0]] is the smallest and arrin[indx[n-1]] the largest double value.

The initial values in the index vector are irrelevant.

New heapsort has index counting starts at 0 instead of previous NR-type at 1.

heapsort

public static final void heapsort(int n,
                                  int[] arrin,
                                  int[] indx)

Sort an array of integer value in ascending order. The ascending order of the double array is provided through the indx vector. After performing this method, the indx vector contains the ordering of the integer array, i.e. arrin[indx[0]] is the smallest and arrin[indx[n-1]] the largest integer value.

The initial values in the index vector are irrelevant.

New heapsort has index counting starts at 0 instead of previous NR-type at 1.

precision

public static double precision(double x,
                               double p)

Rounds the given number to a certain precision.

Parameters:

x - number

p - precision, e.g. 1e-10