org.britastro.grelf

Class Maths

java.lang.Object

org.britastro.grelf.Maths

public class Maths
extends java.lang.Object

Static methods to do common mathematical calculations. The trigonometrical methods are for ease of working in degrees rather than radians. java.lang.StrictMath methods are always used.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Maths.Statistics Just a record to hold public values.

Method Summary

Methods

Modifier and Type	Method and Description
static double	acosDegs(double cos) Get arccos in degrees.
static double	acosh(double x) Hyperbolic inverse cosine.
static double	angleDifference(double a1degrees, double a2degrees) Find the difference (a1 - a2) between 2 angles in degrees, taking into account periodicity.
static double	angleMean(double... anglesInDegrees) Find the mean of a set of angles, taking into account periodicity.
static Maths.Statistics	angleStatistics(java.util.Collection<java.lang.Double> anglesInDegrees) Calculate the min, max, mean and stdDev (all in degrees) of a list or set of angles, taking into account periodicity.
static Maths.Statistics	angleStatistics(double... anglesInDegrees) Calculate the min, max, mean and stdDev of a set of angles, taking into account periodicity.
static double	asinDegs(double sin) Get arcsin in degrees.
static double	asinh(double x) Hyperbolic inverse sine.
static double	atan2Degs(double sin, double cos) Get atan2 in degrees.
static double	atanh(double x) Hyperbolic inverse tangent.
static double	cosDegs(double xDegs) Get cosine of an angle given in degrees.
static double	in360(double xDegs) Convert angle x (degrees) to lie in range 0..360
static double	sinDegs(double xDegs) Get sine of an angle given in degrees.
static double	tanDegs(double xDegs) Get tangent of an angle in degrees.

Methods inherited from class java.lang.Object

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

Method Detail

angleMean

public static double angleMean(double... anglesInDegrees)

Find the mean of a set of angles, taking into account periodicity. Uses angleStatistics ().

angleDifference

public static double angleDifference(double a1degrees,
                     double a2degrees)

Find the difference (a1 - a2) between 2 angles in degrees, taking into account periodicity. The result is in the range -180..+180.

angleStatistics

public static Maths.Statistics angleStatistics(double... anglesInDegrees)

Calculate the min, max, mean and stdDev of a set of angles, taking into account periodicity. Uses angleDifference () from a working mean of the first angle. Does NOT use the erroneous method you can find on the web that averages sin and cos and then takes atan2.

angleStatistics

public static Maths.Statistics angleStatistics(java.util.Collection<java.lang.Double> anglesInDegrees)

Calculate the min, max, mean and stdDev (all in degrees) of a list or set of angles, taking into account periodicity. Uses angleDifference () from a working mean of the first angle. Does NOT use the erroneous method you can find on the web that averages sin and cos and then takes atan2.

in360

public static double in360(double xDegs)

Convert angle x (degrees) to lie in range 0..360

acosDegs

public static double acosDegs(double cos)

Get arccos in degrees.

asinDegs

public static double asinDegs(double sin)

Get arcsin in degrees.

atan2Degs

public static double atan2Degs(double sin,
               double cos)

Get atan2 in degrees.

sinDegs

public static double sinDegs(double xDegs)

Get sine of an angle given in degrees.

cosDegs

public static double cosDegs(double xDegs)

Get cosine of an angle given in degrees.

tanDegs

public static double tanDegs(double xDegs)

Get tangent of an angle in degrees.

asinh

public static double asinh(double x)

Hyperbolic inverse sine.

acosh

public static double acosh(double x)

Hyperbolic inverse cosine. Returns NaN if the argument is less than 1.

atanh

public static double atanh(double x)

Hyperbolic inverse tangent. Returns NaN if the absolute value of the argument is less than 1.