r - 第 1 组的唯一值，然后是第 1 组和第 2 组的唯一值，依此类推

我有一个包含 5 个不同组的数据框:

   id group
1  L1     1
2  L2     1
3  L1     2
4  L3     2
5  L4     2
6  L3     3
7  L5     3
8  L6     3
9  L1     4
10 L4     4
11 L2     5

我想知道是否有可能从第一组、第一组和第二组、第一组、第二组和第三组等中获得唯一的 id 而无需循环。我正在寻找 dplyr 或 data.table 包的方法。

预期成绩 :

    group      id
1   1          c("L1", "L2")
2   1,2        c("L1", "L2", "L3", "L4")
3   1,2,3      c("L1", "L2", "L3", "L4", "L5")
4   1,2,3,4    c("L1", "L2", "L3", "L4", "L5")
5   1,2,3,4,5  c("L1", "L2", "L3", "L4", "L5")

数据 :

structure(list(id = c("L1", "L2", "L1", "L3", "L4", "L3", "L5",
"L6", "L1", "L4", "L2"), group = structure(c(1L, 1L, 2L, 2L,
2L, 3L, 3L, 3L, 4L, 4L, 5L), .Label = c("1", "2", "3", "4", "5"
), class = "factor")), .Names = c("id", "group"), row.names = c(NA,
-11L), class = "data.frame")

最佳答案

使用基础 R，您可以执行以下操作:

# create the "growing" sets of groups
combi_groups <- lapply(seq_along(unique(df$group)), function(i) unique(df$group)[1:i])

# get the unique ID for each set of groups
uniq_ID <- setNames(lapply(combi_groups, function(x) unique(df$id[df$group %in% x])),
                    sapply(combi_groups, paste, collapse=","))

# $`1`
# [1] "L1" "L2"

# $`1,2`
# [1] "L1" "L2" "L3" "L4"

# $`1,2,3`
# [1] "L1" "L2" "L3" "L4" "L5" "L6"

# $`1,2,3,4`
# [1] "L1" "L2" "L3" "L4" "L5" "L6"

# $`1,2,3,4,5`
# [1] "L1" "L2" "L3" "L4" "L5" "L6"

如果您想按照预期的输出进行格式化:

data.frame(group=sapply(combi_groups, paste, collapse=", "), id=sapply(uniq_ID, function(x) paste0("c(", paste0("\"", x, "\"", collapse=", "), ")")))
#          group                                    id
#1             1                         c("L1", "L2")
#2          1, 2             c("L1", "L2", "L3", "L4")
#3       1, 2, 3 c("L1", "L2", "L3", "L4", "L5", "L6")
#4    1, 2, 3, 4 c("L1", "L2", "L3", "L4", "L5", "L6")
#5 1, 2, 3, 4, 5 c("L1", "L2", "L3", "L4", "L5", "L6")

格式化的另一种可能性:

data.frame(group=rep(names(uniq_ID), sapply(uniq_ID, length)), id=unlist(uniq_ID))

或者，如果您想在一列中包含 uniq_ID:

library(data.table)
data.table(group=sapply(combi_groups, paste, collapse=", "), id=uniq_ID)
#           group                id
#1:             1             L1,L2
#2:          1, 2       L1,L2,L3,L4
#3:       1, 2, 3 L1,L2,L3,L4,L5,L6
#4:    1, 2, 3, 4 L1,L2,L3,L4,L5,L6
#5: 1, 2, 3, 4, 5 L1,L2,L3,L4,L5,L6

data.table(group=sapply(combi_groups, paste, collapse=", "), id=uniq_ID)[2, id]
[[1]]
[1] "L1" "L2" "L3" "L4"

关于r - 第 1 组的唯一值，然后是第 1 组和第 2 组的唯一值，依此类推，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/43866137/