---
title: "atan"
description: "Returns the arc tangent of number"
---

# atan

> Returns the arc tangent of number

**This function is used by Ignition's Expression language.**
## Description
Returns the arc tangent of number, which must be a number. The results will be an angle expressed in radians in the range of -pi/2 through pi/2

## Syntax
`atan(number)`

- Parameters

    - float **number** - The number to get the arc tangent of.

- Results
    - float - The arc tangent of the number provided.

## Examples
```python title="Code Snippet"
atan(.38) //returns 0.3631
```