id_across_datasets function

ID across datasets

Create an ID column in each of the data sets. The ID values will span across the data sets.

id_across_datasets(
  dt_list = NULL,
  id_col_name = "id",
  id_col_position = "first",
  silent = FALSE
)

Arguments

• dt_list: a list of data.table objects
• id_col_name: name of the column that will contain ID values. By default, id_col_name = "id".
• id_col_position: position of the newly created ID column. If id_col_position = "first", the new ID column will be placed as the first column in respective data sets. If id_col_position = "last", the new ID column will be placed as the last column in respective data sets.
• silent: If silent = TRUE, a summary of starting and ending ID values in each data set will not be printed. If silent = FALSE, a summary of starting and ending ID values in each data set will be printed. (default = FALSE)

Returns

the output will be a list of data.table objects.

Examples

# running the examples below requires importing the data.table package.
prep(data.table)
id_across_datasets(
dt_list = list(setDT(copy(mtcars)), setDT(copy(iris))))
id_across_datasets(
dt_list = list(setDT(copy(mtcars)), setDT(copy(iris)), setDT(copy(women))),
id_col_name = "newly_created_id_col",
id_col_position = "last")