搜索一段时间后,我知道这个问题尚未得到解答。假设我有以下向量
v <- c("a", "b", "b", "c","c","c", "d", "d", "d", "d")
如何找到重复次数超过1的值
(应为"c","c","c", "d", "d", "d", "d")
和超过2个重复
(应为"d", "d", "d", "d"
)
函数duplicated(v)
仅返回具有重复项的值。
答案 0 :(得分:7)
您可以生成table()
,然后检查v
的哪些元素是表格相关子集的一部分,例如
R> v <- c("a", "b", "b", "c","c","c", "d", "d", "d", "d")
R> tab <- table(v)
R> tab
v
a b c d
1 2 3 4
R> v[v %in% names(tab[tab > 2])]
[1] "c" "c" "c" "d" "d" "d" "d"
R> v[v %in% names(tab[tab > 3])]
[1] "d" "d" "d" "d"
答案 1 :(得分:5)
我会使用ave
编写一个这样的简单函数:
myFun <- function(vector, thresh) {
ind <- ave(rep(1, length(vector)), vector, FUN = length)
vector[ind > thresh + 1] ## added "+1" to match your terminology
}
这里适用于“v”:
myFun(v, 1)
# [1] "c" "c" "c" "d" "d" "d" "d"
myFun(v, 2)
# [1] "d" "d" "d" "d"
当然,总有“data.table”:
as.data.table(v)[, N := .N, by = v][N > 1 + 1]$v
# [1] "c" "c" "c" "d" "d" "d" "d"
as.data.table(v)[, N := .N, by = v][N > 2 + 1]$v
# [1] "d" "d" "d" "d"