How to select the rows with maximum values in each group with dplyr? [duplicate]
Try this:
result <- df %>%
group_by(A, B) %>%
filter(value == max(value)) %>%
arrange(A,B,C)
Seems to work:
identical(
as.data.frame(result),
ddply(df, .(A, B), function(x) x[which.max(x$value),])
)
#[1] TRUE
As pointed out in the comments, slice may be preferred here as per @RoyalITS' answer below if you strictly only want 1 row per group. This answer will return multiple rows if there are multiple with an identical maximum value.
df %>% group_by(A,B) %>% slice(which.max(value))