docs-v2/content/flux/v0/stdlib/math/exp.md

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---
title: math.exp() function
description: >
`math.exp()` returns `e**x`, the base-e exponential of `x`.
menu:
flux_v0_ref:
name: math.exp
parent: math
identifier: math/exp
weight: 101
---
<!------------------------------------------------------------------------------
IMPORTANT: This page was generated from comments in the Flux source code. Any
edits made directly to this page will be overwritten the next time the
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To make updates to this documentation, update the function comments above the
function definition in the Flux source code:
https://github.com/influxdata/flux/blob/master/stdlib/math/math.flux#L755-L755
Contributing to Flux: https://github.com/influxdata/flux#contributing
Fluxdoc syntax: https://github.com/influxdata/flux/blob/master/docs/fluxdoc.md
------------------------------------------------------------------------------->
`math.exp()` returns `e**x`, the base-e exponential of `x`.
##### Function type signature
```js
(x: float) => float
```
{{% caption %}}
For more information, see [Function type signatures](/flux/v0/function-type-signatures/).
{{% /caption %}}
## Parameters
### x
({{< req >}})
Value to operate on.
## Examples
- [Return the base-e exponential of a value](#return-the-base-e-exponential-of-a-value)
- [Use math.exp in map](#use-mathexp-in-map)
### Return the base-e exponential of a value
```js
import "math"
math.exp(x: 21.0)// 1.3188157344832146e+09
```
### Use math.exp in map
```js
import "sampledata"
import "math"
sampledata.float()
|> map(fn: (r) => ({r with _value: math.exp(x: r._value)}))
```
{{< expand-wrapper >}}
{{% expand "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 | 0.11304153064044985 | t1 |
| 2021-01-01T00:00:10Z | 55270.798943169066 | t1 |
| 2021-01-01T00:00:20Z | 1556.1965278371533 | t1 |
| 2021-01-01T00:00:30Z | 41037629.64620374 | t1 |
| 2021-01-01T00:00:40Z | 4114385.297453036 | t1 |
| 2021-01-01T00:00:50Z | 83.93141691026881 | t1 |
| _time | _value | *tag |
| -------------------- | -------------------- | ---- |
| 2021-01-01T00:00:00Z | 417585553.5730289 | t2 |
| 2021-01-01T00:00:10Z | 144.02688737091955 | t2 |
| 2021-01-01T00:00:20Z | 0.023517745856009107 | t2 |
| 2021-01-01T00:00:30Z | 385480050.5181745 | t2 |
| 2021-01-01T00:00:40Z | 1045493.9383645338 | t2 |
| 2021-01-01T00:00:50Z | 6.423736771429135 | t2 |
{{% /expand %}}
{{< /expand-wrapper >}}