gov.sns.tools.math
Class ElementaryFunction

java.lang.Object
  |
  +--gov.sns.tools.math.ElementaryFunction

public final class ElementaryFunction

extends java.lang.Object

Utility case for defining elementary mathemtical functions that are not, but should be, included in the java.Math class.

Field Summary

static double

EPS small tolerance value

Constructor Summary

ElementaryFunction()

Method Summary

static double	acosh(double x) Inverse hyperbolic cosine function.
static double	asinh(double x) Inverse hyperbolic sine function.
static double	atanh(double x) Inverse hyperbolic tangent function.
static double	cosh(double x) Hyperbolic cosine function.
static double	sinc(double x) sinc function = sin(x)/x For small values of x we Taylor expand the sine function to sixth order, sinc(x) = 1 - x^2/6 + x^4/120 - x^6/5040 + O(x^8) otherwise we return Math.sin(x)/x.
static double	sinch(double x) sinch function = sinh(x)/x For small values of x we Taylor expand the hyperbolic sine function to sixth order, sinch(x) = 1 + x^2/6 + x^4/120 + x^6/5040 + O(x^8) otherwise we return sinh(x)/x.
static double	sinh(double x) Hyperbolic sine function.
static double	tanh(double x) Hyperbolic tangent function.

Methods inherited from class java.lang.Object

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

Field Detail

EPS

public static final double EPS

small tolerance value

See Also:

Constant Field Values

Constructor Detail

ElementaryFunction

public ElementaryFunction()

Method Detail

sinc

public static double sinc(double x)

sinc function = sin(x)/x For small values of x we Taylor expand the sine function to sixth order, sinc(x) = 1 - x^2/6 + x^4/120 - x^6/5040 + O(x^8) otherwise we return Math.sin(x)/x.

Parameters:

x - any real number

sinch

public static double sinch(double x)

sinch function = sinh(x)/x For small values of x we Taylor expand the hyperbolic sine function to sixth order, sinch(x) = 1 + x^2/6 + x^4/120 + x^6/5040 + O(x^8) otherwise we return sinh(x)/x.

Parameters:

x - any real number

sinh

public static final double sinh(double x)

Hyperbolic sine function. This should really be included in Java.

Parameters:

x - any real number

cosh

public static final double cosh(double x)

Hyperbolic cosine function. This too.

Parameters:

x - any real number

tanh

public static final double tanh(double x)

Hyperbolic tangent function.

asinh

public static final double asinh(double x)

Inverse hyperbolic sine function.

Parameters:

x - any real number

acosh

public static final double acosh(double x)
                          throws java.lang.IllegalArgumentException

Inverse hyperbolic cosine function. Note that due to the nature of the hyperbolic cosine function the argument must be greater than 1.0.

Parameters:

x - a real number in the interval [1,+inf)

Throws:

java.lang.IllegalArgumentException - argument value is outside the domain of definition

atanh

public static final double atanh(double x)
                          throws java.lang.IllegalArgumentException

Inverse hyperbolic tangent function. Note that do to the nature of the inverse hyperbolic tangent function overflow may occur for arguments close to the values -1 and 1.

Parameters:

x - a real number in the open interval (-1,1)

Throws:

java.lang.IllegalArgumentException - argument value is outside the domain of definition