Find timerange based on the change of a value

Fluxlang
4

@Sven_Achtelik I think you could accomplish this with the events.duration() function. It’s a little convoluted, but you’d first have to logically assign a _level of either crit, warn, info, or ok, then use the monitor.stateChangesOnly() function (which depends on those four levels). Then ungroup and sort by time again (since monitor.stateChangesOnly() changes the grouping and sorting). Then with the output of events.duration(), you can calculate the stop time by adding the returned duration to the start time of the state:

import "influxdata/influxdb/monitor"
import "contrib/tomhollingworth/events"

from(bucket: "example-bucket")
  |> range(start: -15m)
  |> filter(fn: (r) => r.field == "sensor1")
  |> map(fn: (r) => ({ r with _level: if r._value >= 1000 then "crit" else "ok" }))
  |> monitor.stateChangesOnly()
  |> group()
  |> sort(columns: ["_time"])  
  |> events.duration(unit: 1ns, stop: now())
  |> map(fn: (r) => ({ 
    state: if r._level == "crit" then "on" else "off",
    start_time: r._time,
    stop_time: time(v: int(v: r._time) + r.duration),
  }))

The resulting output will look something like:

state start_time stop_time
off 02020-12-22T20:48:08Z 2020-12-22T20:48:18Z
on 2020-12-22T20:48:18Z 2020-12-22T20:48:28Z
off 2020-12-22T20:48:28Z 2020-12-22T20:48:58Z
on 2020-12-22T20:48:58Z 2020-12-22T20:49:08Z
off 2020-12-22T20:49:08Z 2020-12-22T20:49:58Z
on 2020-12-22T20:49:58Z 2020-12-22T20:58:27Z
2 Likes