Question

How to use add_tally() and add_count()? What are they used for?

Answer 1

Hey,

add_tally and add_count returns the count of rows similar to count( ).

add_tally() adds a column n to a table based on the number of items within each existing group, while add_count() is a shortcut that does the grouping as well. 

Syntax:

add_tally(x, wt, sort = FALSE, name = "n")
add_count(x, ..., wt = NULL, sort = FALSE, name = "n")

Example -

mtcars %>% add_count(cyl)
mtcars %>% group_by(cyl) >%> add_tally()

Hope it helps!