derivative() function

Warning! This page documents an earlier version of Flux, which is no longer actively developed. Flux v0.36 is the most recent stable version of Flux.

The derivative() function computes the rate of change per unit of time between subsequent non-null records. The output table schema will be the same as the input table.

Function type: Aggregate
Output data type: Float

derivative(unit: 100ms, nonNegative: false, columns: ["_value"], timeSrc: "_time")

Parameters

unit

The time duration used when creating the derivative.

Data type: Duration

nonNegative

Indicates if the derivative is allowed to be negative. When set to true, if a value is less than the previous value, it is assumed the previous value should have been a zero.

Data type: Boolean

columns

A list of columns on which to compute the derivative. Defaults to ["_value"]

Data type: Array of strings

timeSrc

The column containing time values. Defaults to "_time".

Data type: String

Examples

from(bucket: "telegraf/autogen")
  |> range(start: -5m)
  |> derivative(unit: 100ms, nonNegative: true)

DERIVATIVE()