---
title: math.atan() function
description: math.atan() returns the arctangent of x in radians.
url: https://docs.influxdata.com/flux/v0/stdlib/math/atan/
estimated_tokens: 1399
product: Flux
version: v0
---

# math.atan() function

-   Flux 0.22.0+
-   View InfluxDB support

`math.atan()` returns the arctangent of `x` in radians.

##### Function type signature

```js
(x: float) => float
```

For more information, see [Function type signatures](/flux/v0/function-type-signatures/).

## Parameters

### x

(Required) Value to operate on.

## Examples

-   [Return the arctangent of a value](#return-the-arctangent-of-a-value)
-   [Use math.atan in map](#use-mathatan-in-map)

### Return the arctangent of a value

```js
import "math"

math.atan(x: 3.14)// 1.262480664599468

```

### Use math.atan in map

```js
import "math"
import "sampledata"

sampledata.float()
    |> map(fn: (r) => ({r with _value: math.atan(x: r._value)}))
```

[](#view-example-input-and-output)

View example input and output

#### Input data

| _time | *tag | _value |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | t1 | -2.18 |
| 2021-01-01T00:00:10Z | t1 | 10.92 |
| 2021-01-01T00:00:20Z | t1 | 7.35 |
| 2021-01-01T00:00:30Z | t1 | 17.53 |
| 2021-01-01T00:00:40Z | t1 | 15.23 |
| 2021-01-01T00:00:50Z | t1 | 4.43 |

| _time | *tag | _value |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | t2 | 19.85 |
| 2021-01-01T00:00:10Z | t2 | 4.97 |
| 2021-01-01T00:00:20Z | t2 | -3.75 |
| 2021-01-01T00:00:30Z | t2 | 19.77 |
| 2021-01-01T00:00:40Z | t2 | 13.86 |
| 2021-01-01T00:00:50Z | t2 | 1.86 |

#### Output data

| _time | _value | *tag |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | -1.140718191739034 | t1 |
| 2021-01-01T00:00:10Z | 1.4794759377086963 | t1 |
| 2021-01-01T00:00:20Z | 1.4355721950708649 | t1 |
| 2021-01-01T00:00:30Z | 1.5138130181922385 | t1 |
| 2021-01-01T00:00:40Z | 1.5052305597197282 | t1 |
| 2021-01-01T00:00:50Z | 1.3487837105541014 | t1 |

| _time | _value | *tag |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | 1.5204610466686876 | t2 |
| 2021-01-01T00:00:10Z | 1.3722402258799695 | t2 |
| 2021-01-01T00:00:20Z | -1.3101939350475555 | t2 |
| 2021-01-01T00:00:30Z | 1.520257709140084 | t2 |
| 2021-01-01T00:00:40Z | 1.4987710606562659 | t2 |
| 2021-01-01T00:00:50Z | 1.0774963946058176 | t2 |