---
title: math.erfc() function
description: math.erfc() returns the complementary error function of x.
url: https://docs.influxdata.com/flux/v0/stdlib/math/erfc/
estimated_tokens: 1611
product: Flux
version: v0
---

# math.erfc() function

-   Flux 0.22.0+
-   View InfluxDB support

`math.erfc()` returns the complementary error function 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 complementary error function of a value](#return-the-complementary-error-function-of-a-value)
-   [Use math.erfc in map](#use-matherfc-in-map)

### Return the complementary error function of a value

```js
import "math"

math.erfc(x: 22.6)// 3.772618913849058e-224

```

### Use math.erfc in map

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

sampledata.float()
    |> map(fn: (r) => ({r with _value: math.erfc(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 | 1.9979506490526588 | t1 |
| 2021-01-01T00:00:10Z | 0.000000000000000000000000000000000000000000000000000008381980138107252 | t1 |
| 2021-01-01T00:00:20Z | 0.000000000000000000000000262744434287864 | t1 |
| 2021-01-01T00:00:30Z | 0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011164884065025777 | t1 |
| 2021-01-01T00:00:40Z | 0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000006790933091004747 | t1 |
| 2021-01-01T00:00:50Z | 0.0000000003729065687554446 | t1 |

| _time | _value | *tag |
| --- | --- | --- |
| 2021-01-01T00:00:00Z | 0.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002144458719979885 | t2 |
| 2021-01-01T00:00:10Z | 0.0000000000020855419929990413 | t2 |
| 2021-01-01T00:00:20Z | 1.9999998862727435 | t2 |
| 2021-01-01T00:00:30Z | 0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000005123973574678553 | t2 |
| 2021-01-01T00:00:40Z | 0.00000000000000000000000000000000000000000000000000000000000000000000000000000000000015161509817813512 | t2 |
| 2021-01-01T00:00:50Z | 0.008527511664360422 | t2 |