R 使用分组变量确定所有可能的项目组合

这相当棘手，而且相当缓慢，因为有23625个指定的三组可能的组合

n <- 2

all_pairs <- lapply(list1, function(group) {
  all_combs <- apply(combn(ncol(combn(length(group), n)), length(list1)), 
                     2,
        function(x) c(combn(length(group), n)[,x]), simplify = FALSE)
  
  all_combs[sapply(all_combs, function(x) !any(duplicated(x)))]
})

index_df <- do.call(expand.grid, lapply(all_pairs, function(x) seq(length(x))))

result <- apply(index_df, 1, function(x) {
  m <- t(sapply(seq_along(x), function(y) list1[[y]][all_pairs[[y]][[x[y]]]]))
  setNames(lapply(split(m, (seq_along(m)-1) %/% (length(list1) * n)),
         function(x) c(t(matrix(x, ncol = n)))), names(list1))
}, simplify = FALSE)

结果列表如下所示:

head(result)
#> [[1]]
#> [[1]]$Group_1
#> [1] "1"  "2"  "13" "14" "19" "20"
#> 
#> [[1]]$Group_2
#> [1] "3"  "4"  "15" "16" "21" "22"
#> 
#> [[1]]$Group_3
#> [1] "5"  "6"  "17" "18" "23" "24"
#> 
#> 
#> [[2]]
#> [[2]]$Group_1
#> [1] "1"  "2"  "13" "14" "19" "20"
#> 
#> [[2]]$Group_2
#> [1] "3"  "5"  "15" "16" "21" "22"
#> 
#> [[2]]$Group_3
#> [1] "4"  "6"  "17" "18" "23" "24"
#> 
#> 
#> [[3]]
#> [[3]]$Group_1
#> [1] "1"  "2"  "13" "14" "19" "20"
#> 
#> [[3]]$Group_2
#> [1] "3"  "6"  "15" "16" "21" "22"
#> 
#> [[3]]$Group_3
#> [1] "4"  "5"  "17" "18" "23" "24"
#> 
#> 
#> [[4]]
#> [[4]]$Group_1
#> [1] "1"  "3"  "13" "14" "19" "20"
#> 
#> [[4]]$Group_2
#> [1] "2"  "4"  "15" "16" "21" "22"
#> 
#> [[4]]$Group_3
#> [1] "5"  "6"  "17" "18" "23" "24"
#> 
#> 
#> [[5]]
#> [[5]]$Group_1
#> [1] "1"  "3"  "13" "14" "19" "20"
#> 
#> [[5]]$Group_2
#> [1] "2"  "5"  "15" "16" "21" "22"
#> 
#> [[5]]$Group_3
#> [1] "4"  "6"  "17" "18" "23" "24"
#> 
#> 
#> [[6]]
#> [[6]]$Group_1
#> [1] "1"  "3"  "13" "14" "19" "20"
#> 
#> [[6]]$Group_2
#> [1] "2"  "6"  "15" "16" "21" "22"
#> 
#> [[6]]$Group_3
#> [1] "4"  "5"  "17" "18" "23" "24"

由reprex package(v2.0.1)于2022-06-09创建