---
title: math.atanh() function
description: math.atanh() returns the inverse hyperbolic tangent of x.
url: https://docs.influxdata.com/flux/v0/stdlib/math/atanh/
estimated_tokens: 1409
product: Flux
version: v0
---

# math.atanh() function

-   Flux 0.22.0+
-   View InfluxDB support

`math.atanh()` returns the inverse hyperbolic tangent of `x`.

##### 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.

`x` should be greater than -1 and less than 1. Otherwise the operation will return `NaN`.

## Examples

-   [Return the hyperbolic tangent of a value](#return-the-hyperbolic-tangent-of-a-value)
-   [Use math.atanh in map](#use-mathatanh-in-map)

### Return the hyperbolic tangent of a value

```js
import "math"

math.atanh(x: 0.22)// 0.22365610902183242

```

### Use math.atanh in map

```js
import "math"

data
    |> map(fn: (r) => ({r with _value: math.atanh(x: r._value)}))
```

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

View example input and output

#### Input data

| _time | *tag | _value |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | t1 | -0.021800000000000003 |
| 2021-01-01T00:00:10Z | t1 | 0.1092 |
| 2021-01-01T00:00:20Z | t1 | 0.0735 |
| 2021-01-01T00:00:30Z | t1 | 0.1753 |
| 2021-01-01T00:00:40Z | t1 | 0.15230000000000002 |
| 2021-01-01T00:00:50Z | t1 | 0.0443 |

| _time | *tag | _value |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | t2 | 0.1985 |
| 2021-01-01T00:00:10Z | t2 | 0.0497 |
| 2021-01-01T00:00:20Z | t2 | -0.0375 |
| 2021-01-01T00:00:30Z | t2 | 0.1977 |
| 2021-01-01T00:00:40Z | t2 | 0.1386 |
| 2021-01-01T00:00:50Z | t2 | 0.018600000000000002 |

#### Output data

| _time | _value | *tag |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | -0.021803454395720394 | t1 |
| 2021-01-01T00:00:10Z | 0.10963718917920522 | t1 |
| 2021-01-01T00:00:20Z | 0.07363278579671062 | t1 |
| 2021-01-01T00:00:30Z | 0.17712951464974935 | t1 |
| 2021-01-01T00:00:40Z | 0.1534942122028045 | t1 |
| 2021-01-01T00:00:50Z | 0.04432901360668446 | t1 |

| _time | _value | *tag |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | 0.2011705409124157 | t2 |
| 2021-01-01T00:00:10Z | 0.049740981912241244 | t2 |
| 2021-01-01T00:00:20Z | -0.037517592971457035 | t2 |
| 2021-01-01T00:00:30Z | 0.20033786359692538 | t2 |
| 2021-01-01T00:00:40Z | 0.13949787194848565 | t2 |
| 2021-01-01T00:00:50Z | 0.01860214539735061 | t2 |