docs-v2/content/flux/v0/stdlib/universe/elapsed.md

title	description	menu	weight	flux/v0/tags	introduced
elapsed() function	`elapsed()` returns the time between subsequent records.	flux_v0_ref name parent identifier elapsed universe universe/elapsed	101	transformations	0.36.0

elapsed() returns the time between subsequent records.

For each input table, elapsed() returns the same table without the first row (because there is no previous time to derive the elapsed time from) and an additional column containing the elapsed time.

Function type signature

(<-tables: stream[A], ?columnName: string, ?timeColumn: string, ?unit: duration) => stream[B] where A: Record, B: Record

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Parameters

unit

Unit of time used in the calculation. Default is 1s.

timeColumn

Column to use to compute the elapsed time. Default is _time.

columnName

Column to store elapsed times in. Default is elapsed.

tables

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

Examples

Calculate the time between points in seconds

import "sampledata"

sampledata.int()
    |> elapsed(unit: 1s)

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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

_time	_value	*tag	elapsed
2021-01-01T00:00:10Z	10	t1	10
2021-01-01T00:00:20Z	7	t1	10
2021-01-01T00:00:30Z	17	t1	10
2021-01-01T00:00:40Z	15	t1	10
2021-01-01T00:00:50Z	4	t1	10

_time	_value	*tag	elapsed
2021-01-01T00:00:10Z	4	t2	10
2021-01-01T00:00:20Z	-3	t2	10
2021-01-01T00:00:30Z	19	t2	10
2021-01-01T00:00:40Z	13	t2	10
2021-01-01T00:00:50Z	1	t2	10

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