coalesce                Return first non-missing element
dcast                   Convert data between wide and long forms.
dt_count                Additional useful functions
dt_left_join            Join two data.frames by common columns.
dt_mutate               'dplyr'-like interface for data.table.
let_if                  Modify, aggregate, select or filter
                        data.frame/data.table
maditr                  maditr: Pipe-Style Interface for 'data.table'
query_if                One-to-one interface for data.table '[' method
to_list                 Apply an expression to each element of a list
                        or vector
vlookup                 Look up values in dictionary.
