df
a = c("aa", "bb", "cc", "bb", "bb", "cc","bb", "bb", "cc", "cc", "bb", "cc", "bb", "bb", "cc","bb", "bb", "cc", "cc", "bb","bb")
b = c("aa", "bb", "cc", "bb", "bb", "cc","bb", "bb", "cc", "cc", "bb", "cc", "bb", "bb", "cc","bb", "bb", "cc", "cc", "bb","bb")
c = c("aa", "aa", "aa", "bb", "bb", "cc","bb", "bb", "cc", "cc", "bb", "cc", "bb", "bb", "cc","bb", "bb", "cc", "cc", "bb","bb")
d = c(1, 1, 2, 2, 3, 3, 1, 1, 1, 1, 1, 1, 2, 2, 3, 3, 1, 1, 1, 1, 1)
df = data.frame(a,b,c,d)
列名:
cols <- c("a","b","c")
功能:
rare_label <- function(x){
freq = prop.table(table(unlist(x)))
make_rare = names(freq)[freq < 0.20]
lapply(x,
function(x) {
replace(x, x %in% make_rare, "Rare")
})}
希望使用 dplyr::mutate(across())
评估 a、b、c 中所有值组合的比例,然后用比例更改任何类别低于 20% 为“稀有”。
输出:
a b c
Rare Rare Rare
bb bb Rare
cc cc Rare
bb bb bb
bb bb bb
cc cc cc
bb bb bb
. . .
. . .
. . .
使用下面的代码会引发错误,我不确定原因。
df %<>%
mutate(across(where(cols), ~rare_label(.)
Error: unexpected symbol in: " mutate(across(where(cols), ~rare_label(.) View"
最佳答案
一个选项可能是:
df %>%
mutate(across(all_of(cols),
~ replace(., . %in% names(which(prop.table(table(.)) < 0.20)), "rare")))
a b c d
1 rare rare rare 1
2 bb bb rare 1
3 cc cc rare 2
4 bb bb bb 2
5 bb bb bb 3
6 cc cc cc 3
7 bb bb bb 1
8 bb bb bb 1
9 cc cc cc 1
10 cc cc cc 1
如果要应用现有函数:
fun <- function(x) replace(x, x %in% names(which(prop.table(table(x)) < 0.20)), "rare")
df %>%
mutate(across(all_of(cols), fun))
https://stackoverflow.com/questions/63731527/