docs-v2/content/flux/v0/stdlib/math/float64frombits.md

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---
title: math.float64frombits() function
description: >
`math.float64frombits()` returns the floating-point number corresponding to the IEE
754 binary representation `b`, with the sign bit of `b` and the result in the
same bit position.
menu:
flux_v0_ref:
name: math.float64frombits
parent: math
identifier: math/float64frombits
weight: 101
---
<!------------------------------------------------------------------------------
IMPORTANT: This page was generated from comments in the Flux source code. Any
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To make updates to this documentation, update the function comments above the
function definition in the Flux source code:
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Contributing to Flux: https://github.com/influxdata/flux#contributing
Fluxdoc syntax: https://github.com/influxdata/flux/blob/master/docs/fluxdoc.md
------------------------------------------------------------------------------->
`math.float64frombits()` returns the floating-point number corresponding to the IEE
754 binary representation `b`, with the sign bit of `b` and the result in the
same bit position.
##### Function type signature
```js
(b: uint) => float
```
{{% caption %}}
For more information, see [Function type signatures](/flux/v0/function-type-signatures/).
{{% /caption %}}
## Parameters
### b
({{< req >}})
Value to operate on.
## Examples
- [Convert bits into a float value](#convert-bits-into-a-float-value)
- [Use math.float64frombits in map](#use-mathfloat64frombits-in-map)
### Convert bits into a float value
```js
import "math"
math.float64frombits(b: uint(v: 4))// 2e-323
```
### Use math.float64frombits in map
```js
import "math"
data
|> map(fn: (r) => ({r with _value: math.float64frombits(b: r._value)}))
```
{{< expand-wrapper >}}
{{% expand "View example input and output" %}}
#### Input data
| _time | _value | *tag |
| -------------------- | -------------------- | ---- |
| 2021-01-01T00:00:00Z | 13835463379248627057 | t1 |
| 2021-01-01T00:00:10Z | 4622337031546119127 | t1 |
| 2021-01-01T00:00:20Z | 4619961382742681190 | t1 |
| 2021-01-01T00:00:30Z | 4625627474023866696 | t1 |
| 2021-01-01T00:00:40Z | 4624763345845364982 | t1 |
| 2021-01-01T00:00:50Z | 4616673755014700728 | t1 |
| _time | _value | *tag |
| -------------------- | -------------------- | ---- |
| 2021-01-01T00:00:00Z | 4626280495969835418 | t2 |
| 2021-01-01T00:00:10Z | 4617281740964395745 | t2 |
| 2021-01-01T00:00:20Z | 13838998704956112896 | t2 |
| 2021-01-01T00:00:30Z | 4626257977971698565 | t2 |
| 2021-01-01T00:00:40Z | 4623992104409177784 | t2 |
| 2021-01-01T00:00:50Z | 4611055514479556035 | t2 |
#### Output data
| _time | _value | *tag |
| -------------------- | ------- | ---- |
| 2021-01-01T00:00:00Z | -2.18 | t1 |
| 2021-01-01T00:00:10Z | 10.92 | t1 |
| 2021-01-01T00:00:20Z | 7.35 | t1 |
| 2021-01-01T00:00:30Z | 17.53 | t1 |
| 2021-01-01T00:00:40Z | 15.23 | t1 |
| 2021-01-01T00:00:50Z | 4.43 | t1 |
| _time | _value | *tag |
| -------------------- | ------- | ---- |
| 2021-01-01T00:00:00Z | 19.85 | t2 |
| 2021-01-01T00:00:10Z | 4.97 | t2 |
| 2021-01-01T00:00:20Z | -3.75 | t2 |
| 2021-01-01T00:00:30Z | 19.77 | t2 |
| 2021-01-01T00:00:40Z | 13.86 | t2 |
| 2021-01-01T00:00:50Z | 1.86 | t2 |
{{% /expand %}}
{{< /expand-wrapper >}}