add_custom_column: Add custom column

In rolap: Obtaining Star Databases from Flat Tables

Add custom column

Description

Add a column returned by a function that takes the data of the flat table as a parameter.

Usage

add_custom_column(ft, name, definition)

## S3 method for class 'flat_table'
add_custom_column(ft, name = NULL, definition)

Arguments

ft	A flat_table object.
name	A string, new column name.
definition	A function that returns a table column.

Value

A flat_table object.

See Also

flat_table

Other flat table transformation functions: remove_instances_without_measures(), replace_empty_values(), replace_string(), replace_unknown_values(), select_attributes(), select_instances(), select_instances_by_comparison(), select_measures(), separate_measures(), transform_attribute_format(), transform_from_values(), transform_to_attribute(), transform_to_measure(), transform_to_values()

Examples

f <- function(table) {
  paste0(table$City, ' - ', table$State)
}

ft <- flat_table('ft_num', ft_num) |>
  add_custom_column(name = 'city_state', definition = f)

rolap documentation built on June 8, 2025, 10:23 a.m.