integral() function

integral() computes the area under the curve per unit of time of subsequent non-null records.

integral() requires _start and _stop columns that are part of the group key. The curve is defined using _time as the domain and record values as the range.

Function type signature

(
    <-tables: stream[A],
    ?column: string,
    ?interpolate: string,
    ?timeColumn: string,
    ?unit: duration,
) => stream[B] where A: Record, B: Record

Parameters

unit

Unit of time to use to compute the integral.

column

Column to operate on. Default is _value.

timeColumn

Column that contains time values to use in the operation. Default is _time.

interpolate

Type of interpolation to use. Default is "".

Available interplation types:

• linear
• empty string for no interpolation

tables

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

Examples

• Calculate the integral
• Calculate the integral with linear interpolation

Calculate the integral

data
    |> integral(unit: 10s)

Calculate the integral with linear interpolation

data
    |> integral(unit: 10s, interpolate: "linear")