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

title	description	menu	weight
math.copysign() function	`math.copysign()` returns a value with the magnitude `x` and the sign of `y`.	flux_v0_ref name parent identifier math.copysign math math/copysign	101

math.copysign() returns a value with the magnitude x and the sign of y.

Function type signature

(x: float, y: float) => float

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Parameters

x

({{< req >}}) Magnitude to use in the operation.

y

({{< req >}}) Sign to use in the operation.

Examples

• Return the copysign of two columns
• Use math.copysign in map

Return the copysign of two columns

import "math"

math.copysign(x: 1.0, y: 2.0)

Use math.copysign in map

import "math"

data
    |> map(fn: (r) => ({_time: r._time, _value: math.copysign(x: r.x, y: r.y)}))

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Input data

_time	x	y
2021-01-01T00:00:00Z	1.2	3.9
2021-01-01T01:00:00Z	2.4	-4.2
2021-01-01T02:00:00Z	3.6	5.3
2021-01-01T03:00:00Z	4.8	-6.8
2021-01-01T04:00:00Z	5.1	7.5

Output data

_time	_value
2021-01-01T00:00:00Z	1.2
2021-01-01T01:00:00Z	-2.4
2021-01-01T02:00:00Z	3.6
2021-01-01T03:00:00Z	-4.8
2021-01-01T04:00:00Z	5.1

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