group: Groups Combination
Description
Combines data.frame groups into a unique one
Usage
group(df, collapse = ".", keepNAlevels = FALSE, ...)
Value
a named list containing row indices of grouping combinations.
Arguments
- df
a data.frame whose columns represent grouping factor.
- collapse
a string used to collapse groups levels.
- keepNAlevels
whether to keep NA levels resulting from groups merging
- ...
other arguments to be passed.