docs-v2/content/flux/v0/stdlib/universe/tofloat.md

4.8 KiB

title description menu weight flux/v0/tags introduced
toFloat() function `toFloat()` converts all values in the `_value` column to float types.
flux_v0_ref
name parent identifier
toFloat universe universe/toFloat
101
transformations
type-conversions
0.7.0

toFloat() converts all values in the _value column to float types.

Supported data types

  • string (numeric, scientific notation, ±Inf, or NaN)
  • boolean
  • int
  • uint
Function type signature
(<-tables: stream[{A with _value: B}]) => stream[{A with _value: B, _value: float}]

{{% caption %}} For more information, see Function type signatures. {{% /caption %}}

Parameters

tables

Input data. Default is piped-forward data (<-).

Examples

Convert an integer _value column to floats

import "sampledata"

sampledata.int()
    |> toFloat()

{{< expand-wrapper >}} {{% expand "View example input and output" %}}

Input data

_time _value *tag
2021-01-01T00:00:00Z -2 t1
2021-01-01T00:00:10Z 10 t1
2021-01-01T00:00:20Z 7 t1
2021-01-01T00:00:30Z 17 t1
2021-01-01T00:00:40Z 15 t1
2021-01-01T00:00:50Z 4 t1
_time _value *tag
2021-01-01T00:00:00Z 19 t2
2021-01-01T00:00:10Z 4 t2
2021-01-01T00:00:20Z -3 t2
2021-01-01T00:00:30Z 19 t2
2021-01-01T00:00:40Z 13 t2
2021-01-01T00:00:50Z 1 t2

Output data

_time _value *tag
2021-01-01T00:00:00Z -2 t1
2021-01-01T00:00:10Z 10 t1
2021-01-01T00:00:20Z 7 t1
2021-01-01T00:00:30Z 17 t1
2021-01-01T00:00:40Z 15 t1
2021-01-01T00:00:50Z 4 t1
_time _value *tag
2021-01-01T00:00:00Z 19 t2
2021-01-01T00:00:10Z 4 t2
2021-01-01T00:00:20Z -3 t2
2021-01-01T00:00:30Z 19 t2
2021-01-01T00:00:40Z 13 t2
2021-01-01T00:00:50Z 1 t2

{{% /expand %}} {{< /expand-wrapper >}}

Convert a boolean _value column to floats

import "sampledata"

sampledata.bool()
    |> toFloat()

{{< expand-wrapper >}} {{% expand "View example input and output" %}}

Input data

_time *tag _value
2021-01-01T00:00:00Z t1 true
2021-01-01T00:00:10Z t1 true
2021-01-01T00:00:20Z t1 false
2021-01-01T00:00:30Z t1 true
2021-01-01T00:00:40Z t1 false
2021-01-01T00:00:50Z t1 false
_time *tag _value
2021-01-01T00:00:00Z t2 false
2021-01-01T00:00:10Z t2 true
2021-01-01T00:00:20Z t2 false
2021-01-01T00:00:30Z t2 true
2021-01-01T00:00:40Z t2 true
2021-01-01T00:00:50Z t2 false

Output data

_time *tag _value
2021-01-01T00:00:00Z t1 1
2021-01-01T00:00:10Z t1 1
2021-01-01T00:00:20Z t1 0
2021-01-01T00:00:30Z t1 1
2021-01-01T00:00:40Z t1 0
2021-01-01T00:00:50Z t1 0
_time *tag _value
2021-01-01T00:00:00Z t2 0
2021-01-01T00:00:10Z t2 1
2021-01-01T00:00:20Z t2 0
2021-01-01T00:00:30Z t2 1
2021-01-01T00:00:40Z t2 1
2021-01-01T00:00:50Z t2 0

{{% /expand %}} {{< /expand-wrapper >}}