docs-v2/content/flux/v0.x/stdlib/experimental/universe/mean.md

title	description	menu	weight	flux/v0.x/tags	introduced
mean() function	`mean()` returns the average of non-null values in a specified column from each input table.	flux_0_x_ref name parent identifier mean experimental/universe experimental/universe/mean	201	transformations aggregates	v0.166.0

mean() returns the average of non-null values in a specified column from each input table.

Note: universe.mean() is an experimental function with a more precise type signature.

Function type signature

(<-tables: stream[{B with A: C}], ?column: A = "_value") => stream[{A: C}] where A: Label, B: Record, C: Numeric

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

Parameters

column

Column to use to compute means. Default is _value.

tables

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

Examples

Return the average of values in each input table

import "experimental/universe"
import "sampledata"

sampledata.int()
    |> universe.mean()

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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

*tag	_value
t1	8.5

*tag	_value
t2	8.833333333333334

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