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Version: Java (Groovy)

avgBy

avgBy returns the average (mean) of each non-key column for each group. Null values are ignored.

caution

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​

ParameterTypeDescription
groupByColumnsString...

The column(s) by which to group data.

  • NULL returns total average for all non-key columns.
  • "X" will output the total average of each group in column X.
  • "X", "Y" will output the total average of each group designated from the X and Y columns.
groupByColumnsCollection<String>

The column(s) by which to group data.

  • NULL returns total average for all non-key columns.
  • "X" will output the total average of each group in column X.
  • "X", "Y" will output the total average of each group designated from the X and Y columns.
groupByColumnsColumnName

The column(s) by which to group data.

  • NULL returns total average for all non-key columns.
  • "X" will output the total average of each group in column X.
  • "X", "Y" will output the total average of each group designated from the X and Y columns.

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()

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")

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")