How to access to specify file in subfolder without change working directory In R?

Question

In R, I want to access to some file in subfolder. But I don\'t want to change working directory then move back. It lost time and long.

For exmaple, I working on /

Answer 1

You could use what Hadley calls a closure in Advanced R if I understand what you're after:

## Make a function that takes a path and another function
## and returns that same function with the path pre-progammed in
pathit <- function(FUN, path){
    function(file, ...){
        FUN(file=file.path(path, file), ...)
    }
}

## generate new functions that have the path pre-programmed in
read.csv2b <- pathit(read.csv, "home/phuong/data1")
source2 <- pathit(source, "home/phuong/data2")


read.csv2b("abc.csv")
read.csv2b("def.csv")
source2("pricing.R")

If you have a lot of stuff to read in this may be worthwhile otherwise why not supply the whole path to the actual functions? If this isn't what you're after it was still a fun learning experience for me :-)