coffee                  Coffee Data Set
emergency               Emergency Calls for Montgomery County, PA
fill_by_function        Fill missing values by a function of the
                        nonmissings.
fill_by_prevalent       Fill missing values by the most prevalent
                        nonnmissing value.
fill_by_value           Fill missing values by a single value.
get_interval            Get the interval of a datetime variable.
pad                     Pad the datetime column of a data frame.
thicken                 Add a variable of a higher interval to a data
                        frame.
