How do I interchange a fixed string with a sequential string?
For instance, if I want to repeat a pattern of a string, I would do the following:
> rep(c("Filler","Model"),2)
[1] "Filler" "Model" "Filler" "Model" "Filler" "Model"
But, I want something like this where I can automatically add numbers behind "Model" with each iteration of a repeat:
[1] "Filler" "Model 1" "Filler" "Model 2" "Filler" "Model 3"
Is there a way to combine rep() with sprintf()?
Here is one base R approach. We can access all even elements of the input vector and then paste with a numeric sequence.
x <- rep(c("Filler","Model"),3)
x[c(FALSE, TRUE)] <- paste(x[c(FALSE, TRUE)], c(1:3))
x
[1] "Filler" "Model 1" "Filler" "Model 2" "Filler" "Model 3"
Here is an alternative:
x <- rep(c("Filler","Model"),3)
x[x=="Model"] = paste("Model", seq_along(x[x=="Model"]))
x
[1] "Filler" "Model 1" "Filler" "Model 2" "Filler" "Model 3"
Here is another option if the Filler Model sequence is not always alternating:
x <- c("Filler", "Model", "Filler", "Model", "Model", "Model")
replace(x, which(x == "Model"), paste(x, cumsum(x == "Model"))[which(x == "Model")])
#> [1] "Filler" "Model 1" "Filler" "Model 2" "Model 3" "Model 4"
Or slightly more compact
paste(x, replace(cumsum(x == "Model"), which(x!="Model"), ""))
#> [1] "Filler " "Model 1" "Filler " "Model 2" "Model 3" "Model 4"
