Repeat each element in a string a certain number of times

I'm using the rep() function to repeat each element in a string a number of times. Each character I have contains information for a state, and I need the first three elements of the character vector repeated three times, and the fourth element repeated five times.

So lets say I have the following character vectors.

al <- c("AlabamaCity", "AlabamaCityST", "AlabamaCityState", "AlabamaZipCode") 
ak <- c("AlaskaCity", "AlaskaCityST", "AlaskaCityState", "AlaskaZipCode")
az <- c("ArizonaCity", "ArizonaCityST", "ArizonaCityState", "ArizonaZipCode")
ar <- c("ArkansasCity", "ArkansasCityST", "ArkansasCityState", "ArkansasZipCode")

I want to end up having the following output.

AlabamaCity
AlabamaCity
AlabamaCity
AlabamaCityST
AlabamaCityST
AlabamaCityST
AlabamaCityState
AlabamaCityState
AlabamaCityState
AlabamaZipCode
AlabamaZipCode
AlabamaZipCode
AlabamaZipCode
AlabamaZipCode
AlabamaZipCode
...

I was able to get the desired output with the following command, but it's a little inconvenient when I'm running through all fifty states. Plus, I might have another column with 237 cities in Alabama, and I'll inevitably run into problems mat开发者_StackOverflowching up the names in the first column with the values in the second column.

   dat = data.frame(name=c(rep(al[1:3],each=3), rep(al[4],each=6), 
                rep(ak[1:3],each=3), rep(ak[4],each=6)))
   dat


   dat2 = data.frame(name=c(rep(al[1:3],each=3), rep(al[4],each=6), 
                rep(ak[1:3],each=3), rep(ak[4],each=6)),
                city=c(rep("x",each=15), rep("y",each=15)))
   dat2

Of course, in real life, the 'x' and 'y' won't be single values.

So my question concerns if there is a more efficient way of performing this task. And closely related to the question, when does it become important to ditch procedural programming in favor of OOP in R. (not a programmer, so the second part may be a really stupid question) More importantly, is this a task where I should look for a oop related solution.

---

According to ?rep, times= can be a vector. So, how about this:

dat <- data.frame(name=rep(al, times=c(3,3,3,6)))

It would also be more convenient if your "state" data were in a list.

stateData <- list(al,ak,az,ar)
Data <- lapply(stateData, function(x) data.frame(name=rep(x, times=c(3,3,3,6))))
Data <- do.call(rbind, Data)

---

I think you can combine the times() argument of rep to work through a list with sapply(). So first, we need to make our list object:

vars <- list(al, ak, az, ar)


# Iterate through each object in vars. By default, this returns a column for each list item.
# Convert to vector and then to data.frame...This is probably not that efficient.
as.data.frame(as.vector(sapply(vars, function(x) rep(x, times = c(3,3,3,6)))))

1                                                         AlabamaCity
2                                                         AlabamaCity
3                                                         AlabamaCity
4                                                       AlabamaCityST
....snip....
....snip....
57                                                    ArkansasZipCode
58                                                    ArkansasZipCode
59                                                    ArkansasZipCode
60                                                    ArkansasZipCode

---

You might consider using expand.grid, then paste on the results from that.