org.jscience.mathematics
Class MathUtils

java.lang.Object
  org.jscience.mathematics.MathUtils

public final class MathUtils
extends java.lang.Object

The extra math library. Provides extra functions not in java.lang.Math class. This class cannot be subclassed or instantiated because all methods are static.

Method Summary

static double	acosh(double x) Returns the arc hyperbolic cosine of a double, in the range of 0.0 through .
static double	asinh(double x) Returns the arc hyperbolic sine of a double, in the range of - through .
static double	atanh(double x) Returns the arc hyperbolic tangent of a double, in the range of - through .
static double	binomial(double n, double k) Returns the binomial coefficient (n k).
static int	binomial(int n, int k) Returns the binomial coefficient (n k).
static double	cosh(double x) Returns the hyperbolic cosine of a double.
static double	factorial(double x) Returns the factorial.
static int	GCD(int a, int b)
static double	hypot(double x, double y) Returns sqrt(x2+y2).
static int	LCM(int a, int b)
static double	log10(double x) Returns the base 10 logarithm of a double.
static double	log2(double d)
static double	logB(double d, double d1)
static double	logFactorial(double x) Returns the natural logarithm of the factorial.
static double	maxOf3(double a, double b, double c) �O�‚̎�?
static double	midOf3(double a, double b, double c) �O�‚̎�?
static double	minOf3(double a, double b, double c) �O�‚̎�?
static double[]	pascalTriangle(int n) ���R?
static double	polynomialExpansion(double n, double[] k) Returns the multinomial coefficient (n k[]).
static int	pow(int a, int b) Returns ab.
static int	pow2(int a) Returns 2a.
static double	round(double x, int significant) Rounds a number to so many significant figures.
static double	sigmoid(double x) produces a double between 0 and 1 with (sigmoid(0.5) == 0) being true
static double	sigmoid(double x, double flatteningFactor) sigmoid(double x) is the same as sigmoid(double x, 1), large flatteningFactor flattens the curve
static int	sign(double x)
static double	sinh(double x) Returns the hyperbolic sine of a double.
static int	sumOfDigits(long number) returns the sum of all individual digits.
static double	tanh(double x) Returns the hyperbolic tangent of a double.

Methods inherited from class java.lang.Object

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

Method Detail

round

public static double round(double x,
                           int significant)

Rounds a number to so many significant figures.

Parameters:

x - a number to be rounded.

significant - number of significant figures to round to.

hypot

public static double hypot(double x,
                           double y)

Returns sqrt(x²+y²).

pow

public static int pow(int a,
                      int b)

Returns a^b.

Parameters:

a - an integer.

b - a positive integer.

pow2

public static int pow2(int a)

Returns 2^a.

Parameters:

a - a positive integer.

factorial

public static double factorial(double x)

Returns the factorial. (Wrapper for the gamma function).

Parameters:

x - a double.

See Also:

SpecialMathUtils.gamma(double)

logFactorial

public static double logFactorial(double x)

Returns the natural logarithm of the factorial. (Wrapper for the log gamma function).

Parameters:

x - a double.

See Also:

SpecialMathUtils.logGamma(double)

binomial

public static int binomial(int n,
                           int k)

Returns the binomial coefficient (n k). Uses Pascal's recursion formula.

Parameters:

n - an integer.

k - an integer.

binomial

public static double binomial(double n,
                              double k)

Returns the binomial coefficient (n k). Uses gamma functions.

Parameters:

n - a double.

k - a double btween 0 and n.

polynomialExpansion

public static double polynomialExpansion(double n,
                                         double[] k)

Returns the multinomial coefficient (n k[]). Uses gamma functions.

Parameters:

n - a double.

k[] - a double array such that k1 + k2 + k3 + ... + km = n (unchecked).

GCD

public static int GCD(int a,
                      int b)

LCM

public static int LCM(int a,
                      int b)

log10

public static double log10(double x)

Returns the base 10 logarithm of a double.

Parameters:

x - a double.

logB

public static double logB(double d,
                          double d1)

log2

public static double log2(double d)

sinh

public static double sinh(double x)

Returns the hyperbolic sine of a double.

Parameters:

x - a double.

cosh

public static double cosh(double x)

Returns the hyperbolic cosine of a double.

Parameters:

x - a double.

tanh

public static double tanh(double x)

Returns the hyperbolic tangent of a double.

Parameters:

x - a double.

asinh

public static double asinh(double x)

Returns the arc hyperbolic sine of a double, in the range of - through .

Parameters:

x - a double.

acosh

public static double acosh(double x)

Returns the arc hyperbolic cosine of a double, in the range of 0.0 through .

Parameters:

x - a double.

atanh

public static double atanh(double x)

Returns the arc hyperbolic tangent of a double, in the range of - through .

Parameters:

x - a double.

sign

public static int sign(double x)

maxOf3

public static double maxOf3(double a,
                            double b,
                            double c)

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Parameters:

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b - ��?�

c - ��?�

Returns:

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See Also:

midOf3(double,double,double), minOf3(double,double,double)

midOf3

public static double midOf3(double a,
                            double b,
                            double c)

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Parameters:

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b - ��?�

c - ��?�

Returns:

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See Also:

maxOf3(double,double,double), minOf3(double,double,double)

minOf3

public static double minOf3(double a,
                            double b,
                            double c)

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Parameters:

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b - ��?�

c - ��?�

Returns:

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See Also:

maxOf3(double,double,double), midOf3(double,double,double)

sigmoid

public static double sigmoid(double x)

produces a double between 0 and 1 with (sigmoid(0.5) == 0) being true

sigmoid

public static double sigmoid(double x,
                             double flatteningFactor)

sigmoid(double x) is the same as sigmoid(double x, 1), large flatteningFactor flattens the curve

sumOfDigits

public static int sumOfDigits(long number)

returns the sum of all individual digits. Example: sumOfDigits(123045) returns 15 (1+2+3+4+0+5).

pascalTriangle

public static double[] pascalTriangle(int n)

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Parameters:

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Returns:

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