Mathematics with two variables

Fluxlang
,
1

Hi how can use the value from my first variable as a divisor in my second variable?

import "math"

latencyAverage = from(bucket:"telegraf")
    |> range(start: v.timeRangeStart, stop: v.timeRangeStop )
    |> filter(fn: (r) => r.host == "PRG-host")
    |> filter(fn: (r) => r._measurement == "nping_UDP")
    |> filter(fn: (r) => r["nping-dest"] == "qt-brazil")
    |> filter(fn: (r) => (r._field == "nping-avg"))
    |> mean()
    |> first()
    |> rename(columns: { "_value": "latencyAverage_values" })
   //|> yield(name:"latencyAverage")

jitter = from(bucket:"telegraf")
    |> range(start: v.timeRangeStart, stop: v.timeRangeStop )
    |> filter(fn: (r) => r.host == "PRG-host")
    |> filter(fn: (r) => r._measurement == "nping_UDP")
    |> filter(fn: (r) => r["nping-dest"] == "qt-brazil")
    |> filter(fn: (r) => (r._field == "nping-avg") or (r._field == "nping-pl_prct"), onEmpty: "keep")
    |> map(fn: (r) => ({r with latency_values:  float(v:r._value)}))
    |> map(fn: (r) => ({r with packetLoss_values:  float(v:r["nping-pl_prct"])}))
    |> filter(fn: (r) => r.latency_values <= 49 or r.packetLoss_values <=1)
    |> map(fn: (r) => ({r with latency_values: float(v: r["nping-avg"]), 
                            percentage_values: float(v: r["nping-pl_prct"])}))
    |> aggregateWindow(every:5m, fn: mean, createEmpty: true)    
    |> toFloat()
    |> pivot(rowKey:["_time"], columnKey: ["_field"], valueColumn: "_value")
    |> map(fn: (r) => ({r with finalResult: r["nping-avg"]/latencyAverage}))
    |> yield(name: "jitter")

This is my code and the last map() uses latencyAverage

2

Here latencyAverage and jutter are both streams of tables.

You want to get the _value in the first row in the first table.

Sometimes this will do it

|> findColumn(fn: (key) => key._field == field, column: "_value")

or sometimes you seem to need the more cumbersome

(tables|> tableFind(fn: (key) => true) |> getColumn(column: "_value"))[0]