---
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
---

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`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)}))

```

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{{% 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 >}}