docs-v2/content/flux/v0.x/stdlib/math/acos.md

title	description	menu	weight
math.acos() function	`math.acos()` returns the acosine of `x` in radians.	flux_0_x_ref name parent identifier math.acos math math/acos	101

math.acos() returns the acosine of x in radians.

Function type signature

(x: float) => float

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

Parameters

x

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

x should be greater than -1 and less than 1. Otherwise, the operation will return NaN.

Examples

• Return the acosine of a value
• Use math.acos in map

Return the acosine of a value

import "math"

math.acos(x: 0.22)// 1.3489818562981022

Use math.acos in map

import "math"

data
    |> map(fn: (r) => ({r with _value: math.acos(x: r._value)}))

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Input data

_time	*tag	_value
2021-01-01T00:00:00Z	t1	-0.021800000000000003
2021-01-01T00:00:10Z	t1	0.1092
2021-01-01T00:00:20Z	t1	0.0735
2021-01-01T00:00:30Z	t1	0.1753
2021-01-01T00:00:40Z	t1	0.15230000000000002
2021-01-01T00:00:50Z	t1	0.0443

_time	*tag	_value
2021-01-01T00:00:00Z	t2	0.1985
2021-01-01T00:00:10Z	t2	0.0497
2021-01-01T00:00:20Z	t2	-0.0375
2021-01-01T00:00:30Z	t2	0.1977
2021-01-01T00:00:40Z	t2	0.1386
2021-01-01T00:00:50Z	t2	0.018600000000000002

Output data

_time	_value	*tag
2021-01-01T00:00:00Z	1.592598053869604	t1
2021-01-01T00:00:10Z	1.461378125419181	t1
2021-01-01T00:00:20Z	1.4972299878346804	t1
2021-01-01T00:00:30Z	1.3945858483452276	t1
2021-01-01T00:00:40Z	1.417901321254124	t1
2021-01-01T00:00:50Z	1.5264818242659286	t1

_time	_value	*tag
2021-01-01T00:00:00Z	1.3709690985581462	t2
2021-01-01T00:00:10Z	1.5210758434398064	t2
2021-01-01T00:00:20Z	1.6083051214238853	t2
2021-01-01T00:00:30Z	1.3717852736930785	t2
2021-01-01T00:00:40Z	1.4317486962850596	t2
2021-01-01T00:00:50Z	1.5521952541518969	t2

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