这是df的一个例子:
df <- structure(list(x = 1:30, y = 101:130, g = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L), .Label = c("A", "B", "C"), class = "factor")), .Names = c("x", "y", "g"), row.names = c(NA, -30L), class = "data.frame")
我想在过滤后的数据中获得每组10个最低y值.
但
df2 <- df %>% filter(x>3) %>% group_by(g) %>% tail(y, n=10)
仅返回最后一组的行(在本例中为C):
Source: local data frame [10 x …