%notin%                 The inverse of %in%
aggro                   Aggregates a numerical column
count                   Count the number of occurences of every unique
                        element in a data object
left                    Get the specified left most characters of a
                        string
right                   Get the specified right most characters of a
                        string
round_something         The function round_something() does numerical
                        rounding with a specified number of decimals.
                        The 'something' will typically be a data.frame
                        with mixed column types, of which the numerical
                        columns must be rounded. This function makes
                        that easier: all non-numerical columns are left
                        in place, the numerical columns are rounded.
                        Columns that are character but can be
                        interpreted as numerical are first converted to
                        numerical, and then rounded.
se                      Standard Error
