Maths (Starlink-UK API)

java.lang.Object
- uk.ac.starlink.ttools.func.Maths

```
public class Maths
extends Object
```
Standard mathematical and trigonometric functions. Trigonometric functions work with angles in radians.

Since:

2 Sep 2004

Author:

Mark Taylor (Starlink)

Field Summary

Fields
Modifier and Type	Field and Description
`static double`	`E` Euler's number e, the base of natural logarithms.
`static double`	`Infinity` Positive infinite floating point value.
`static double`	`NaN` Not-a-Number floating point value.
`static double`	`PI` Pi, the ratio of the circumference of a circle to its diameter.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static double`	`acos(double x)` Arc cosine of an angle.
`static double`	`acosh(double x)` Inverse hyperbolic cosine.
`static double`	`asin(double x)` Arc sine of an angle.
`static double`	`asinh(double x)` Inverse hyperbolic sine.
`static double`	`atan(double x)` Arc tangent of an angle.
`static double`	`atan2(double y, double x)` Converts rectangular coordinates (`x`,`y`) to polar (`r`,`theta`).
`static double`	`atanh(double x)` Inverse hyperbolic tangent.
`static double`	`cos(double theta)` Cosine of an angle.
`static double`	`cosh(double x)` Hyperbolic cosine.
`static double`	`exp(double x)` Euler's number e raised to a power.
`static double`	`exp10(double x)` Power of 10.
`static double`	`hypot(double... xs)` Returns the square root of the sum of squares of its arguments.
`static double`	`ln(double x)` Natural logarithm.
`static double`	`log10(double x)` Logarithm to base 10.
`static double`	`pow(double a, double b)` Exponentiation.
`static double`	`sin(double theta)` Sine of an angle.
`static double`	`sinh(double x)` Hyperbolic sine.
`static double`	`sqrt(double x)` Square root.
`static double`	`square(double x)` Raise to the power 2.
`static double`	`symlog(double linthresh, double linscale, double x)` Symmetric logarithm mapping function.
`static double`	`tan(double theta)` Tangent of an angle.
`static double`	`tanh(double x)` Hyperbolic tangent.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - E
```
public static final double E
```
    Euler's number e, the base of natural logarithms.
    
    See Also:
    
    Constant Field Values
  - PI
```
public static final double PI
```
    Pi, the ratio of the circumference of a circle to its diameter.
    
    See Also:
    
    Constant Field Values
  - Infinity
```
public static final double Infinity
```
    Positive infinite floating point value.
    
    See Also:
    
    Constant Field Values
  - NaN
```
public static final double NaN
```
    Not-a-Number floating point value. Use with care; arithmetic and logical operations behave in strange ways near NaN (for instance, NaN!=NaN). For most purposes this is equivalent to the blank value.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - sin
```
public static double sin(double theta)
```
    Sine of an angle.
    
    Parameters:
    
    theta - an angle, in radians.
    
    Returns:
    
    the sine of the argument.
  - cos
```
public static double cos(double theta)
```
    Cosine of an angle.
    
    Parameters:
    
    theta - an angle, in radians.
    
    Returns:
    
    the cosine of the argument.
  - tan
```
public static double tan(double theta)
```
    Tangent of an angle.
    
    Parameters:
    
    theta - an angle, in radians.
    
    Returns:
    
    the tangent of the argument.
  - asin
```
public static double asin(double x)
```
    Arc sine of an angle. The result is in the range of -pi/2 through pi/2.
    
    Parameters:
    
    x - the value whose arc sine is to be returned.
    
    Returns:
    
    the arc sine of the argument (radians)
  - acos
```
public static double acos(double x)
```
    Arc cosine of an angle. The result is in the range of 0.0 through pi.
    
    Parameters:
    
    x - the value whose arc cosine is to be returned.
    
    Returns:
    
    the arc cosine of the argument (radians)
  - atan
```
public static double atan(double x)
```
    Arc tangent of an angle. The result is in the range of -pi/2 through pi/2.
    
    Parameters:
    
    x - the value whose arc tangent is to be returned.
    
    Returns:
    
    the arc tangent of the argument (radians)
  - ln
```
public static double ln(double x)
```
    Natural logarithm.
    
    Parameters:
    
    x - argument
    
    Returns:
    
    log_e(x)
  - exp
```
public static double exp(double x)
```
    Euler's number e raised to a power.
    
    Parameters:
    
    x - the exponent to raise e to.
    
    Returns:
    
    the value e^x, where e is the base of the natural logarithms.
  - log10
```
public static double log10(double x)
```
    Logarithm to base 10.
    
    Parameters:
    
    x - argument
    
    Returns:
    
    log₁₀(x)
  - exp10
```
public static double exp10(double x)
```
    Power of 10. This convenience function is identical to pow(10,x).
    
    Parameters:
    
    x - argument
    
    Returns:
    
    10^x
  - sqrt
```
public static double sqrt(double x)
```
    Square root. The result is correctly rounded and positive.
    
    Parameters:
    
    x - a value.
    
    Returns:
    
    the positive square root of x. If the argument is NaN or less than zero, the result is NaN.
  - square
```
public static double square(double x)
```
    Raise to the power 2.
    
    Parameters:
    
    x - a value
    
    Returns:
    
    x * x
  - hypot
```
public static double hypot(double... xs)
```
    Returns the square root of the sum of squares of its arguments. In the 2-argument case, doing it like this may avoid intermediate overflow or underflow.
    
    Parameters:
    
    xs - one or more numeric values
    
    Returns:
    
    sqare root of sum of squares of arguments
  - atan2
```
public static double atan2(double y,
                           double x)
```
    Converts rectangular coordinates (x,y) to polar (r,theta). This method computes the phase theta by computing an arc tangent of y/x in the range of -pi to pi.
    
    Parameters:
    
    y - the ordinate coordinate
    
    x - the abscissa coordinate
    
    Returns:
    
    the theta component (radians) of the point (r,theta) in polar coordinates that corresponds to the point (x,y) in Cartesian coordinates.
  - pow
```
public static double pow(double a,
                         double b)
```
    Exponentiation. The result is the value of the first argument raised to the power of the second argument.
    
    Parameters:
    
    a - the base.
    
    b - the exponent.
    
    Returns:
    
    the value a^b.
  - sinh
```
public static double sinh(double x)
```
    Hyperbolic sine.
    
    Parameters:
    
    x - parameter
    
    Returns:
    
    result
  - cosh
```
public static double cosh(double x)
```
    Hyperbolic cosine.
    
    Parameters:
    
    x - parameter
    
    Returns:
    
    result
  - tanh
```
public static double tanh(double x)
```
    Hyperbolic tangent.
    
    Parameters:
    
    x - parameter
    
    Returns:
    
    result
  - asinh
```
public static double asinh(double x)
```
    Inverse hyperbolic sine.
    
    Parameters:
    
    x - parameter
    
    Returns:
    
    result
  - acosh
```
public static double acosh(double x)
```
    Inverse hyperbolic cosine.
    
    Parameters:
    
    x - parameter
    
    Returns:
    
    result
  - atanh
```
public static double atanh(double x)
```
    Inverse hyperbolic tangent.
    
    Parameters:
    
    x - parameter
    
    Returns:
    
    result
  - symlog
```
public static double symlog(double linthresh,
                            double linscale,
                            double x)
```
    Symmetric logarithm mapping function. This function is not generally of much mathematical use, but it is available as one of the scaling options for plot axes. It is linear near the origin (abs(x)<=linthresh) and positive/negative logarithmic outside that region.
    The function is:
```
    |x| <= linthresh:
         x * linscale / linthresh
    |x| >= linthresh:
         sgn(x) * (linscale + log10(|x|) - log10(linthresh))
 
```
    Parameters:
    
    linthresh - linear threshold, below which absolute value the function is linear; must be >0
    
    linscale - linear scale, being the ratio of the half-extent of the linear mapped region to the extent of a decade in the logarithmic region; must be >0
    
    x - value to map
    
    Returns:
    
    mapped value

Class Maths

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

E

PI

Infinity

NaN

Method Detail

sin

cos

tan

asin

acos

atan

ln

exp

log10

exp10

sqrt

square

hypot

atan2

pow

sinh

cosh

tanh

asinh

acosh

atanh

symlog