Mean / List Layer

Calculate the arithmetic mean (average) of values in each variable-length numeric list. Similar to numpy.mean() or R's mean(). Returns a floating-point column containing the average of non-null values in each list.

Example transformation:

lists	mean
[1, 2, 3, 4]	2.5
[10.5, 11.5]	11.0
[-1, 0, 1]	0.0
[100]	100.0
[1, null, 3]	2.0
[]	null
[null, null]	null

Common applications:

Calculating average prices
Computing mean temperatures
Analyzing central tendencies
Finding average response times
Measuring typical usage levels
Computing score averages

Note: Only works with numeric lists. Null values are ignored in mean calculation unless list is empty or contains only nulls, then returns null. Lists can have any length. Result is always floating-point, even for integer inputs.

Table

Select

column

The variable-length numeric list column to average. Examples:

Daily temperatures: [22.5, 23.1, 21.8, 22.3]
Test scores: [85, 92, 88, 90]
Response times: [0.12, 0.15, 0.11]
Measurements: [1.1, 1.2, null, 1.3] Lists can have different lengths. Only numeric types supported.

AsColumn

name

Name for the new column. If not provided, the system generates a unique name. If AsColumn matches an existing column, the existing column is replaced. The name should follow valid column naming conventions.