cat_compare             Calculate the frequency of discrete values in
                        one categorical variable for each group within
                        another categorical variable
cat_contrast            Calculate the frequency of discrete values in
                        one categorical variable for each of two
                        mutually exclusive groups within another
                        categorical variable
cat_count               Count the frequency of discrete values in the
                        column of a dataframe
cat_summarise           Summarise the values of a numerical variable
                        for each group within a categorical variable
cat_vcount              Count the frequency of discrete values in a
                        categorical vector
