top_n {dplyr} | R Documentation |
This is a convenient wrapper that uses filter
and
min_rank
to select the top or bottom entries in each group,
ordered by wt
.
top_n(x, n, wt)
x |
a |
n |
number of rows to return. If If |
wt |
(Optional). The variable to use for ordering. If not specified, defaults to the last variable in the tbl. |
df <- data.frame(x = c(10, 4, 1, 6, 3, 1, 1)) df %>% top_n(2) # Negative values select bottom from group. Note that we get more # than 2 values here because there's a tie: top_n() either takes # all rows with a value, or none. df %>% top_n(-2) if (require("Lahman")) { # Find 10 players with most games # A little nicer with %>% tbl_df(Batting) %>% group_by(playerID) %>% tally(G) %>% top_n(10) # Find year with most games for each player tbl_df(Batting) %>% group_by(playerID) %>% top_n(1, G) }