Paste together two character vectors of different lengths

问题

I have two different character vectors in R, that I want to combine to use for column names:

groups <- c("Group A", "Group B")
label <- c("Time","Min","Mean","Max")

When I try using paste I get the result:

> paste(groups,label)
[1] "Group A Time" "Group B Min"  "Group A Mean" "Group B Max"

Is there a simple function or setting that can paste these together to get the following output?

[1] "Group A Time" "Group A Min"  "Group A Mean" "Group A Max"  "Group B Time"
[6] "Group B Min"  "Group B Mean" "Group B Max" 

回答1:

Probably outer helps your work. Try this:

> c(t(outer(groups, label, paste)))
[1] "Group A Time" "Group A Min"  "Group A Mean" "Group A Max"  "Group B Time" "Group B Min" 
[7] "Group B Mean" "Group B Max" 

回答2:

outer

outer(groups, labels, FUN=paste)

回答3:

Since it's two element array, I would do

 c(paste(groups[1],label),paste(groups[2],label))

来源：https://stackoverflow.com/questions/7287406/paste-together-two-character-vectors-of-different-lengths