Documentation

derivative() function

derivative() computes the rate of change per unit of time between subsequent non-null records.

The function assumes rows are ordered by the _time.

Output tables

The output table schema will be the same as the input table. For each input table with n rows, derivative() outputs a table with n - 1 rows.

Function type signature
(
    <-tables: stream[A],
    ?columns: [string],
    ?initialZero: bool,
    ?nonNegative: bool,
    ?timeColumn: string,
    ?unit: duration,
) => stream[B] where A: Record, B: Record
For more information, see Function type signatures.

Parameters

unit

Time duration used to calculate the derivative. Default is 1s.

nonNegative

Disallow negative derivative values. Default is false.

When true, if a value is less than the previous value, the function assumes the previous value should have been a zero.

columns

List of columns to operate on. Default is ["_value"].

timeColumn

Column containing time values to use in the calculation. Default is _time.

initialZero

Use zero (0) as the initial value in the derivative calculation when the subsequent value is less than the previous value and nonNegative is true. Default is false.

tables

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

Examples

Calculate the non-negative rate of change per second

import "sampledata"

sampledata.int()
    |> derivative(nonNegative: true)

View example input and output

Calculate the rate of change per second with null values

import "sampledata"

sampledata.int(includeNull: true)
    |> derivative()

View example input and output


Was this page helpful?

Thank you for your feedback!


Linux Package Signing Key Rotation

All signed InfluxData Linux packages have been resigned with an updated key. If using Linux, you may need to update your package configuration to continue to download and verify InfluxData software packages.

For more information, see the Linux Package Signing Key Rotation blog post.

InfluxDB Cloud backed by InfluxDB IOx

All InfluxDB Cloud organizations created on or after January 31, 2023 are backed by the new InfluxDB IOx storage engine. Check the right column of your InfluxDB Cloud organization homepage to see which InfluxDB storage engine you’re using.

If powered by IOx, this is the correct documentation.

If powered by TSM, see the TSM-based InfluxDB Cloud documentation.

InfluxDB Cloud backed by InfluxDB TSM

All InfluxDB Cloud organizations created on or after January 31, 2023 are backed by the new InfluxDB IOx storage engine which enables nearly unlimited series cardinality and SQL query support. Check the right column of your InfluxDB Cloud organization homepage to see which InfluxDB storage engine you’re using.

If powered by TSM, this is the correct documentation.

If powered by IOx, see the IOx-based InfluxDB Cloud documentation.

State of the InfluxDB Cloud (IOx) documentation

The new documentation for InfluxDB Cloud backed by InfluxDB IOx is a work in progress. We are adding new information and content almost daily. Thank you for your patience!

If there is specific information you’re looking for, please submit a documentation issue.