## cds.astro Class Trigo

```java.lang.Object
cds.astro.Trigo
```

public class Trigo
extends java.lang.Object

Trigonometric functions. Extracted from Class Coo

Version:
1.0
Author:
Francois Ochsenbein

 Field Summary `static double` `DEG`

 Constructor Summary `Trigo()`

 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` `sinc(double x)`           Function sinc(x) = sin(x)/x `static double` `sind(double x)`           Sin 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 `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

 Field Detail

### DEG

`public static final double DEG`
Constant Field Values
 Constructor Detail

### Trigo

`public Trigo()`
 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)`
Sin 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