avgBy
avgBy
returns the average (mean) of each nonkey column for each group. Null values are ignored.
Applying this aggregation to a column where the average cannot be computed will result in an error. For example, the average is not defined for a column of string values.
Syntax
table.avgBy()
table.avgBy(groupByColumns...)
Parameters
Parameter  Type  Description 

groupByColumns  String...  The column(s) by which to group data.

groupByColumns  Collection<String>  The column(s) by which to group data.

groupByColumns  ColumnName  The column(s) by which to group data.

Returns
A new table containing the average for each group.
Examples
In this example, avgBy
returns the average value for the table. Because an average cannot be computed for the string columns X
and Y
, these columns are dropped before applying avgBy
.
source = newTable(
stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
stringCol("Y", "M", "N", "O", "N", "P", "M", "O", "P", "M"),
intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)
result = source.dropColumns("X", "Y").avgBy()
 source
 result
In this example, avgBy
returns the average value, as grouped by X
. Because an average cannot be computed for the string column Y
, this column is dropped before applying avgBy
.
source = newTable(
stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
stringCol("Y", "M", "N", "O", "N", "P", "M", "O", "P", "M"),
intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)
result = source.dropColumns("Y").avgBy("X")
 source
 result
In this example, avgBy
returns the average value, as grouped by X
and Y
.
source = newTable(
stringCol("X", "A", "B", "A", "C", "B", "A", "B", "B", "C"),
stringCol("Y", "M", "N", "O", "N", "P", "M", "O", "P", "M"),
intCol("Number", 55, 76, 20, 130, 230, 50, 73, 137, 214),
)
result = source.avgBy("X", "Y")
 source
 result