Question

I am trying to concatenate many vectors in R using c(). I have declared each of them to end with “_n” (i.e. filename_n). Now I want to know whether there is an easier method to read them all than just entering in each variable. I know in Bash I can use ls *.file_extension > filename to read all files in. Is there a similar method in R.

Thanks.

Answer 1

From what I understand you might benefit from reading ?list.files, ?read.table, ?do.call, ?sapply. As a means of example,

files = list.files(pattern="*.txt", path = ".")
all = lapply(files, read.table, sep=",")
combined = do.call(c, all)

(untested)

EDIT: it looks like you’re after ?ls and ?get now,

vars = lapply(ls(pattern = "_n"), get)
do.call(c, vars)

or, more succinctly,

sapply(ls(pattern = "_n"), get)