.grouped_list: Split data frame into a list by grouping variable
Description
This function splits the data frame into a list, with the length of the list
equal to the factor levels of the grouping variable.
Usage
.grouped_list(data, grouping.var)
Arguments
data
A data frame (or a tibble) from which variables specified are to
be taken. Other data types (e.g., matrix,table, array, etc.) will not
be accepted. Additionally, grouped data frames from {dplyr} should be
ungrouped before they are entered as data.