cds.astro
Class AstroMath

java.lang.Object
  cds.astro.AstroMath

public class AstroMath
extends java.lang.Object

Trigonometric and a few other functions used in the astronomical context. This class includes also 3x3 matrix manipulation. Extracted from Class Coo

Version:

1.0: 20-Apr-2004

Author:

Francois Ochsenbein

Field Summary

static double	ARCSEC
static double	DEG
static double[]	powers

Constructor Summary

AstroMath()

Method Summary

static double	asinc(double x) Function asinc(x), inverse function of sinc
static double	asind(double x) sin-1 (inverse function of sine), gives argument in degrees
static double	atan2d(double y, double x) get the polar angle from 2-D cartesian coordinates
static double	atand(double x) tan-1 (inverse function of tangent), gives argument in degrees
static double	atanh(double x) tanh-1 (inverse function of tanh)
static double	cosd(double x) Cosine when argument in degrees
static double	cosh(double x) Hyperbolic cosine cosh = (exp(x) + exp(-x))/2
static double	dexp(double x) Compute just 10x
static double	dexp(int n) Compute just 10n
static double	log(double x) Compute the log base 10
static double[][]	m3p(double[][] A, double[][] B) 3-Matrices Products
static double[][]	m3t(double[][] A) Transposed of a Matrix
static double	sinc(double x) Function sinc(x) = sin(x)/x
static double	sind(double x) Sine when argument in degrees
static double	tanh(double x) Hyperbolic tangent = (exp(x)-exp(-x))/(exp(x)+exp(-x))

Methods inherited from class java.lang.Object

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

Field Detail

powers

public static final double[] powers

DEG

public static final double DEG

See Also:

Constant Field Values

ARCSEC

public static final double ARCSEC

See Also:

Constant Field Values

Constructor Detail

AstroMath

public AstroMath()

Method Detail

cosd

public static final double cosd(double x)

Cosine when argument in degrees

Parameters:

x - angle in degrees

Returns:

the cosine

sind

public static final double sind(double x)

Sine when argument in degrees

Parameters:

x - angle in degrees

Returns:

the sine

asind

public static final double asind(double x)

sin-1 (inverse function of sine), gives argument in degrees

Parameters:

x - argument

Returns:

y value such that sin(y) = x

atand

public static final double atand(double x)

tan-1 (inverse function of tangent), gives argument in degrees

Parameters:

x - argument

Returns:

angle in degrees

atan2d

public static final double atan2d(double y,
                                  double x)

get the polar angle from 2-D cartesian coordinates

Parameters:

y - cartesian y coordinate

x - cartesian x coordinate

Returns:

polar angle in degrees

cosh

public static final double cosh(double x)

Hyperbolic cosine cosh = (exp(x) + exp(-x))/2

Parameters:

x - argument

Returns:

corresponding hyperbolic cosine (>= 1)

tanh

public static final double tanh(double x)

Hyperbolic tangent = (exp(x)-exp(-x))/(exp(x)+exp(-x))

Parameters:

x - argument

Returns:

corresponding hyperbolic tangent (in range ]-1, 1[)

atanh

public static final double atanh(double x)

tanh-1 (inverse function of tanh)

Parameters:

x - argument, in range ]-1, 1[ (NaN returned otherwise)

Returns:

corresponding hyperbolic inverse tangent

sinc

public static final double sinc(double x)

Function sinc(x) = sin(x)/x

Parameters:

x - argument (radians)

Returns:

corresponding value

asinc

public static final double asinc(double x)

Function asinc(x), inverse function of sinc

Parameters:

x - argument

Returns:

y such that sinc(y) = x

dexp

public static final double dexp(int n)

Compute just 10ⁿ

Parameters:

n - Power to which to compute the value

Returns:

10ⁿ

dexp

public static final double dexp(double x)

Compute just 10^x

Parameters:

x - Power to which to compute the value

Returns:

10^x

log

public static final double log(double x)

Compute the log base 10

Parameters:

x - Number (positive)

Returns:

log₁₀(x)

m3p

public static final double[][] m3p(double[][] A,
                                   double[][] B)

3-Matrices Products

Parameters:

A - 3x3 matrix

B - 3x3 matrix

Returns:

R = A * B

m3t

public static final double[][] m3t(double[][] A)

Transposed of a Matrix

Parameters:

A - input matric

Returns:

R = ^t(A)