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# get_r2d

Return a constant that converts radians to degrees. Available in version 6.4.0 and later.

## Prototype

```load "\$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"  ; This library is automatically loaded
; from NCL V6.2.0 onward.
; No need for user to explicitly load.

function get_r2d (
val  : numeric or string
)

return_val [scalar] :  float or double
```

## Arguments

val

If val is type numeric, and val is type "double", the returned constant will be type double; otherwise it will be type float.

If val is type string, and val="double" or val="d", the returned constant will be type double; otherwise it will be type float.

It is recommended that the value returned be the same numeric type as the variable(s) with which it will be used.

## Return value

The returned scalar will be type double or float.

## Description

A constant that is used to convert radians to degrees:

```      r2d = 180/PI
```

It is recommended that the value returned by get_r2d (get_d2r and get_pi) be the same numeric type as the variable(s) with which it will be used.

## Examples

Example 1: In these examples, the 'r2d' to the left of the assignment can be any name (eg, 'radians_to_degrees', 'rad_to_deg', 'rad2deg', etc.'). 'r2d' is used for convenience.

```
r2d  = get_r2d("double")   ; type double; 57.29577951308232
r2d  = get_r2d("float" )   ; type float ; 57.29578

r2d  = get_r2d("d")        ; type double; 57.29577951308232
r2d  = get_r2d("f")        ; type float ; 57.29578

r2d  = get_r2d(1d0)        ; type double
r2d  = get_r2d(1.0)        ; type float
r2d  = get_r2d( 1 )        ; type float

xf   = 2.412
xd   = 2.412d0
xi   = 100

r2d  = get_r2d(xd)         ; type double; same type as 'xd'
r2d  = get_r2d(xf)         ; type float ; same type as 'xf'
r2d  = get_r2d(xi)         ; type float
```