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

title	description	menu	weight
math.erfinv() function	`math.erfinv()` returns the inverse error function of `x`.	flux_v0_ref name parent identifier math.erfinv math math/erfinv	101

math.erfinv() returns the inverse error function of x.

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 inverse error function of a value
• Use math.erfinv in map

Return the inverse error function of a value

import "math"

math.erfinv(x: 0.22)// 0.19750838337227364

Use math.erfinv in map

import "math"

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

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Input data

_time	_value	*tag
2021-01-01T00:00:00Z	-0.9979506490526588	t1
2021-01-01T00:00:10Z	1	t1
2021-01-01T00:00:20Z	1	t1
2021-01-01T00:00:30Z	1	t1
2021-01-01T00:00:40Z	1	t1
2021-01-01T00:00:50Z	0.9999999996270934	t1

_time	_value	*tag
2021-01-01T00:00:00Z	1	t2
2021-01-01T00:00:10Z	0.9999999999979144	t2
2021-01-01T00:00:20Z	-0.9999998862727434	t2
2021-01-01T00:00:30Z	1	t2
2021-01-01T00:00:40Z	1	t2
2021-01-01T00:00:50Z	0.9914724883356396	t2

Output data

_time	_value	*tag
2021-01-01T00:00:00Z	-2.1800000000000006	t1
2021-01-01T00:00:10Z	+Inf	t1
2021-01-01T00:00:20Z	+Inf	t1
2021-01-01T00:00:30Z	+Inf	t1
2021-01-01T00:00:40Z	+Inf	t1
2021-01-01T00:00:50Z	4.429999992395194	t1

_time	_value	*tag
2021-01-01T00:00:00Z	+Inf	t2
2021-01-01T00:00:10Z	4.969999434158999	t2
2021-01-01T00:00:20Z	-3.7499999999520366	t2
2021-01-01T00:00:30Z	+Inf	t2
2021-01-01T00:00:40Z	+Inf	t2
2021-01-01T00:00:50Z	1.860000000000001	t2

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