tally {dplyr} | R Documentation |
tally
is a convenient wrapper for summarise that will either call
n
or sum(n)
depending on whether you're tallying
for the first time, or re-tallying. count()
is similar, but also
does the group_by
for you.
tally(x, wt, sort = FALSE) count(x, ..., wt = NULL, sort = FALSE) count_(x, vars, wt = NULL, sort = FALSE)
x |
a |
wt |
(Optional) If omitted, will count the number of rows. If specified,
will perform a "weighted" tally by summing the (non-missing) values of
variable |
sort |
if |
..., vars |
Variables to group by. |
if (require("Lahman")) { batting_tbl <- tbl_df(Batting) tally(group_by(batting_tbl, yearID)) tally(group_by(batting_tbl, yearID), sort = TRUE) # Multiple tallys progressively roll up the groups plays_by_year <- tally(group_by(batting_tbl, playerID, stint), sort = TRUE) tally(plays_by_year, sort = TRUE) tally(tally(plays_by_year)) # This looks a little nicer if you use the infix %>% operator batting_tbl %>% group_by(playerID) %>% tally(sort = TRUE) # count is even more succinct - it also does the grouping for you batting_tbl %>% count(playerID) batting_tbl %>% count(playerID, wt = G) batting_tbl %>% count(playerID, wt = G, sort = TRUE) }