---
title: "atan"
canonical: "https://help.vicon.com/space/ShogunPost121/1253737193/atan"
format: markdown
---
# Description

Returns the arc tangent (aka inverse tangent) of an input

Arc tangent is the inverse function for tangent. Given a value for val, it will return an angle atan(val) in degrees.

To illustrate, picture the unit circle (a circle of radius 1.0 centered about the origin). Imagine a unit vector rotating inside of the unit circle. Draw a perpendicular line (tangent line) from the endpoint of the unit vector to closest point where the perpendicular line would intersect the x-axis. The length of that perpendicular (tangent) line is the input argument val. The angle in degrees between the positive x-axis and the unit vector is the output of the function atan(val).

## Functional area

Math

# Command syntax

## Syntax

> Macro (scroll-tablelayout)

|  |
| --- |
| `atan value` |

### Arguments

| Name | Type | Required | Comments |
| --- | --- | --- | --- |
| `value` | float | yes | The domain of arc tangent is [-Inf, Inf] |

### Flags

None

## Return value

float

Returns a floating point angle in degrees 

> Macro (scroll-pagebreak)

## Examples

```plaintext
float $temp = (atan (0.800)); 
// declares a variable for the arc tan function
 
print (string ($temp)); 
// prints the output of the arc or inverse tan function
```

# Additional information

## Related commands

- [acos](https://vicon-help.atlassian.net/wiki/spaces/ShogunPost121/pages/1253737439)
- [asin](https://vicon-help.atlassian.net/wiki/spaces/ShogunPost121/pages/1253737453)
- [cos](https://vicon-help.atlassian.net/wiki/spaces/ShogunPost121/pages/1253736839)
- [sin](https://vicon-help.atlassian.net/wiki/spaces/ShogunPost121/pages/1253738349)
- [tan](https://vicon-help.atlassian.net/wiki/spaces/ShogunPost121/pages/1253737400)