WCSLIB: wcsmath.h File Reference

WCSLIB 6.2

Macros
wcsmath.h File Reference

Go to the source code of this file.

## Macros
#define | PI 3.141592653589793238462643
#define | D2R PI/180.0
| Degrees to radians conversion factor. More...
#define | R2D 180.0/PI
| Radians to degrees conversion factor. More...
#define | SQRT2 1.4142135623730950488
#define | SQRT2INV 1.0/SQRT2
#define | UNDEFINED 987654321.0e99
| Value used to indicate an undefined quantity. More...
#define | undefined(value) (value == UNDEFINED)
| Macro used to test for an undefined quantity. More...

## Detailed Description

Definition of mathematical constants used by WCSLIB.

## Macro Definition Documentation

## ◆ PI

#define PI 3.141592653589793238462643

## ◆ D2R

#define D2R PI/180.0

Factor to convert from degrees to radians.

## ◆ R2D

#define R2D 180.0/PI

Factor to convert from radians to degrees.

## ◆ SQRT2

#define SQRT2 1.4142135623730950488

, used only by molset() (`MOL` projection).

## ◆ SQRT2INV

#define SQRT2INV 1.0/SQRT2

, used only by qscx2s() (`QSC` projection).

## ◆ UNDEFINED

#define UNDEFINED 987654321.0e99

Value used to indicate an undefined quantity (noting that NaNs cannot be used portably).

## ◆ undefined

#define undefined | ( |  | value | ) | (value == UNDEFINED)

Macro used to test for an undefined value.