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math.y0() function

content/flux/v0/stdlib/math/y0.md

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<!------------------------------------------------------------------------------ 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 documentation is generated. 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#L2233-L2233 Contributing to Flux: https://github.com/influxdata/flux#contributing Fluxdoc syntax: https://github.com/influxdata/flux/blob/master/docs/fluxdoc.md ------------------------------------------------------------------------------->

math.y0() returns the order-zero Bessel function of the second kind.

Function type signature
js
(x: float) => float

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

Parameters

x

({{< req >}}) Value to operate on.

Examples

Return the order-zero Bessel function of a value

js
import "math"

math.y0(x: 3.14)// 0.3289375969127807

Use math.y0 in map

js
import "math"
import "sampledata"

sampledata.float()
    |> map(fn: (r) => ({r with _value: math.y0(x: r._value)}))

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

Input data

_time*tag_value
2021-01-01T00:00:00Zt1-2.18
2021-01-01T00:00:10Zt110.92
2021-01-01T00:00:20Zt17.35
2021-01-01T00:00:30Zt117.53
2021-01-01T00:00:40Zt115.23
2021-01-01T00:00:50Zt14.43
_time*tag_value
2021-01-01T00:00:00Zt219.85
2021-01-01T00:00:10Zt24.97
2021-01-01T00:00:20Zt2-3.75
2021-01-01T00:00:30Zt219.77
2021-01-01T00:00:40Zt213.86
2021-01-01T00:00:50Zt21.86

Output data

_time_value*tag
2021-01-01T00:00:00ZNaNt1
2021-01-01T00:00:10Z-0.15517570189175475t1
2021-01-01T00:00:20Z0.07687091351245329t1
2021-01-01T00:00:30Z-0.16329326302215585t1
2021-01-01T00:00:40Z0.19531314382470338t1
2021-01-01T00:00:50Z-0.17300760424559283t1
_time_value*tag
2021-01-01T00:00:00Z0.03710847827981653t2
2021-01-01T00:00:10Z-0.3039299357361664t2
2021-01-01T00:00:20ZNaNt2
2021-01-01T00:00:30Z0.023033101962350977t2
2021-01-01T00:00:40Z0.10257274599514705t2
2021-01-01T00:00:50Z0.4897750655109666t2

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