Question

以下向量是示例数据框中列名的向量：

x <- c("Col1", "Blah", paste0("M", seq(from = 1, to = 24)), "Ma", "Mam", "Mel", "Stuff")

我想将列名M1，M2，...，M12替换为January，February，...，{ {1}}。理想情况下，我希望我的解决方案是

形式

December

我知道

x[some expression] <- month.name

但我怎样才能匹配> x[grep("M[1-9]$", x)] [1] "M1" "M2" "M3" "M4" "M5" "M6" "M7" "M8" "M9"，"M10"和"M11"？请注意，"M12"到"M13"应不匹配。

Answer 1

您可以使用包stringi直接替换以下列号。

library(stringi)
stri_replace_all_regex(x, paste0("\\bM", 1:12, "\\b"), month.name, vectorize_all = FALSE)
# [1] "Col1"      "Blah"      "January"   "February"  "March"     "April"    
# [7] "May"       "June"      "July"      "August"    "September" "October"  
# [13] "November"  "December"  "M13"       "M14"       "M15"       "M16"      
# [19] "M17"       "M18"       "M19"       "M20"       "M21"       "M22"      
# [25] "M23"       "M24"       "Ma"        "Mam"       "Mel"       "Stuff"

正则表达式：匹配字符串M1，M2，...，M12

1 个答案: