How can I add multiple elements to a vector based on a condition?-CodePudding

Here is what I am trying to accomplish. Say I have this vector

example <- c("a", "b", "N/A", "c", "d", "N/A", "e", "f")

What I am looking to do is for each "N/A", I need to add another one after it. My desired output is

c("a", "b", "N/A", 'N/A", "c", "d", "N/A", "N/A", "e", "f")

for a vector of any length.

I have tried

position <- which(example == "N/A")
for (i in 1:length(example)) {
    append(example, "N/A", after = position[i])
}

but it doesn't work. I think the "after" argument only accepts one value.

CodePudding user response：

This can be done with purrr:map2, Map or mapply:

> unlist(purrr::map2(example, (example == 'N/A')   1, rep))
 [1] "a"   "b"   "N/A" "N/A" "c"   "d"   "N/A" "N/A" "e"   "f"

CodePudding user response：

Try:

> position <- which(example=="N/A")

> for(i in rev(position))
    example <- append(example, "N/A", after=i)

> example
 [1] "a"   "b"   "N/A" "N/A" "c"   "d"   "N/A" "N/A" "e"   "f"