Question

我有一个矢量 Names<-c("A", "B", "C")

我最终会喜欢这样的事情 c("A_Mean", "A_Median", "A_InGroupVar", "B_Mean", "B_Median", "B_InGroupVar", "C_Mean", "C_Median", "C_InGroupVar")

我尝试过粘贴功能 c(paste(Names, "_Mean"), paste(Names, "_Median"), paste(Names, "_InGroupvar"))

但我需要按名称排序矢量。我知道我可以在循环中轻松完成这项工作，但我正在寻找更优雅的解决方案。

Answer 1

这是一种原始方法：

Names <- rep(c("A", "B", "C"), each=3)
Stats <- rep(c("Mean", "Median", "InGroupVar"), 3)
paste(Names, Stats, sep="_")
[1] "A_Mean"       "A_Median"     "A_InGroupVar" "B_Mean"       "B_Median"    
[6] "B_InGroupVar" "C_Mean"       "C_Median"     "C_InGroupVar"

Answer 2

我更喜欢sprintf这个特殊问题：

Names <- c("A", "B", "C")

sprintf("%s_%s", 
        rep(Names, each = 3), 
        c("Mean", "Median", "InGroupVar"))
# [1] "A_Mean"       "A_Median"     "A_InGroupVar" "B_Mean"      
# [5] "B_Median"     "B_InGroupVar" "C_Mean"       "C_Median"    
# [9] "C_InGroupVar"

或者，这也有效，但会以不同的顺序给出结果：

do.call(paste, 
        c(expand.grid(
          Names, c("Mean", "Median", "InGroupVar")), 
          sep = "_"))   
# [1] "A_Mean"       "B_Mean"       "C_Mean"       "A_Median"    
# [5] "B_Median"     "C_Median"     "A_InGroupVar" "B_InGroupVar"
# [9] "C_InGroupVar"

将多个字符串粘贴到一个字符串

2 个答案: