Takes a tibble and groups columns together into a single data column. All
columns that are not row indices will be grouped, and the resulting column
will be named data_name.
colgrp(x, data_name, index_name = "group")
| x | A tibble |
|---|---|
| data_name | A string, the name of the new column |
| index_name | A string, the name of the new column index |
A grouped tibble