如何获得R中字符向量的所有可能子集？

3 回答

• 10

  你可以使用 combn ：

  res <- unlist(lapply(1:3, combn, 
                       x = c("test1","test2","test3"), simplify = FALSE), 
                recursive = FALSE)
  res <- sapply(res, `length<-`, 3)
  #        [,1]    [,2]    [,3]    [,4]    [,5]    [,6]    [,7]   
  #[1,] "test1" "test2" "test3" "test1" "test1" "test2" "test1"
  #[2,] NA      NA      NA      "test2" "test3" "test3" "test2"
  #[3,] NA      NA      NA      NA      NA      NA      "test3"
  

  回复于 2024-05-04T09:15:05+08:00
• 6

  有一套具有相关功能的套装 .

  library(sets)
  a <- c("test1","test2","test3")
  set_power(a)
  

  {{}，{“test1”}，{“test2”}，{“test3”}，{“test1”，“test2”}，{“test1”，“test3”}，{“test2”，“test3 “}，{”test1“，”test2“，”test3“}}

  这将返回所有子集的集合 .

  回复于 2024-05-04T09:15:05+08:00
• 6

  使用combn和data.table :: rbindlist和fill = TRUE选项来生成 NA 值 .

  #data
  a <- c("test1","test2","test3")
  
  #result
  data.table::rbindlist(
          sapply(1:3, function(i) as.data.frame(t(combn(a, i)))), fill = TRUE)
  
  #output
  #       V1    V2    V3
  # 1: test1    NA    NA
  # 2: test2    NA    NA
  # 3: test3    NA    NA
  # 4: test1 test2    NA
  # 5: test1 test3    NA
  # 6: test2 test3    NA
  # 7: test1 test2 test3
  

  回复于 2024-05-04T09:15:05+08:00