我正在尝试修改由dplyr过滤的data.frame,但我似乎不太了解我需要做什么.在下面的例子中,我试图过滤数据框z然后为第三列分配一个新值 - 我举两个例子,一个带有"9",一个带有"NA".
require(dplyr)
z <- data.frame(w = c("a", "a", "a", "b", "c"), x = 1:5, y = c("a", "b", "c", "d", "e"))
z %>% filter(w == "a" & x == 2) %>% select(y)
z %>% filter(w == "a" & x == 2) %>% select(y) <- 9 # Should be similar to z[z$w == "a" & z$ x == 2, 3] <- 9
z %>% filter(w == "a" & x == 3) %>% select(y) <- NA # Should be similar …