---
schema_version: "1"
id: a0a6e0f12283da483ba8c0955388efd56287d6d5490c0e20899ac49213495986
title: atan
collection: mulesoft
version: current
locale: en-us
portal_url: https://docs.salesforce.com/mulesoft/current/en-us/dataweave/2.12/dw-math-functions-atan.md
canonical_url: https://docs.mulesoft.com/dataweave/2.12/dw-math-functions-atan
source_site: docs.mulesoft.com
content_type: documentation
content_hash: 46e1033d09f6e23080688667ef20cc84e4a9026464061977f42746683bfb1b8e
description: MuleSoft Documentation Site
release: "2.12"
latest: false
---
---
product: DataWeave
version: 2.12
---

# atan

> For the full documentation index, see: https://docs.mulesoft.com/llms.txt

## atan(angle: Number): Number

Returns an arc tangent value that can range from `-pi/2` through `pi/2`.

_Introduced in DataWeave version 2.4.0._

### Parameters

<table><colgroup><col> <col></colgroup><thead><tr><th>Name</th><th>Description</th></tr></thead><tbody><tr><td><p><code>angle</code></p></td><td><div><div><p>Number to convert into its arc tangent value.</p></div></div></td></tr></tbody></table>

### Example

This example shows how `atan` behaves with different inputs.

#### Source

```DataWeave
%dw 2.0
import * from dw::util::Math
output application/json
---
{
  "atan0":  atan(0),
  "atan13": atan(0.13),
  "atan-1": atan(-1)
}
```

#### Output

```Json
{
   "atan0": 0.0,
   "atan13": 0.12927500404814307,
   "atan-1": -0.7853981633974483
}
```