Index maps must be a data frame with one integer column
and one character string column.
This function verifies the structure and ensures
that the integer column is first.
Usage
structure_index_map(index_map)
Arguments
- index_map
The index map data frame to be structured.
Value
A data frame with an integer column as the first column
and a character string column as the second column.
Details
This is a non-exported function meant only for internal use.