movingAverage() function

movingAverage() calculates the mean of non-null values using the current value and n - 1 previous values in the _values column.

Moving average rules

• The average over a period populated by n values is equal to their algebraic mean.
• The average over a period populated by only null values is null.
• Moving averages skip null values.
• If n is less than the number of records in a table, movingAverage() returns the average of the available values.

Function type signature

(<-tables: stream[{A with _value: B}], n: int) => stream[{A with _value: float}] where B: Numeric

Parameters

n

(Required) Number of values to average.

tables

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

Examples

• Calculate a three point moving average
• Calculate a three point moving average with null values

Calculate a three point moving average

import "sampledata"

sampledata.int()
    |> movingAverage(n: 3)

Calculate a three point moving average with null values

import "sampledata"

sampledata.int(includeNull: true)
    |> movingAverage(n: 3)