Plot the difference between two stream/data

Fluxlang
1

I have a random data like this:

image
image1255×219 30 KB

The query that I used:

data1 = from(bucket: "testBucket")
  |> range(start: -3h)
  |> ...
  |> yield(name: "data1 ")

data2 = from(bucket: "testBucket")
  |> range(start: -3h)
  |> ...
  |> timeShift(duration: 1h)
  |> yield(name: "data2 ")

How to get and plot the difference between these stream. Basically I want something like this:

data1 - data2

Thanks !!

2

Hi @HarimbolaSantatra

I would use the join.inner() function. You define your two streams as a “left” and “right” side, and use a predicate function on to define how they should match up. Something like this:

import "join"

data1 = from(bucket: "testBucket")
|> range(start: -3h)
|> filter(fn: (r) => r._measurement == "example")
// Ensure data is aligned to the same time grid
|> aggregateWindow(every: 1m, fn: last, createEmpty: false)

data2 = from(bucket: "testBucket")
|> range(start: -3h)
|> filter(fn: (r) => r._measurement == "example")
|> timeShift(duration: 1h)
|> aggregateWindow(every: 1m, fn: last, createEmpty: false)

join.inner(
    left: data1,
    right: data2,
    on: (l, r) => l._time == r._time, 
    as: (l, r) => ({
        _time: l._time,
        // We pull the values from the left and right records
        val1: l._value,
        val2: r._value,
        difference: l._value - r._value
    })
)