---
title: math.log() function
description: math.log() returns the natural logarithm of x.
url: https://docs.influxdata.com/flux/v0/stdlib/math/log/
estimated_tokens: 785
product: Flux
version: v0
---

# math.log() function

-   Flux 0.22.0+
-   View InfluxDB support

`math.log()` returns the natural logarithm 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.

## Examples

-   [Return the natural logarithm of a value](#return-the-natural-logarithm-of-a-value)
-   [Use math.log in map](#use-mathlog-in-map)

### Return the natural logarithm of a value

```js
import "math"

math.log(x: 3.14)// 1.144222799920162

```

### Use math.log in map

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

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