#
Fortran Wiki

atan

## Description

`atan(x)`

computes the arctangent of `x`

.

## Standard

FORTRAN 77 and later, alias for atan2 in Fortran 2008 and later

## Class

Elemental function

## Syntax

`result = atan(x)`

## Arguments

`x`

- The type shall be `real`

.

## Return value

The return value is of type `real`

and it lies in the range $-\pi /2\le atan(x)\le \pi /2$.

## Example

```
program test_atan
real(8) :: x = 2.866_8
x = atan(x)
end program test_atan
```

## See also

atan2, tan

Revised on September 20, 2010 20:43:01
by

Jason Blevins
(174.101.53.244)
(570 characters / 0.0 pages)