[R] UNIX-like "cut" command in R

[Mike Miller]

On Tue, 3 May 2011, Christian Schulz wrote:

>> On Mon, 2 May 2011, P Ehlers wrote:
>> 
>>> Use str_sub() in the stringr package:
>>> 
>>> require(stringr)  # install first if necessary
>>> s <- "abcdefghijklmnopqrstuvwxyz"
>>> 
>>> str_sub(s, c(1,12,17), c(3,15,-1))
>>> #[1] "abc"        "lmno"       "qrstuvwxyz"
>> 
>> 
>> Thanks.  That's very close to what I'm looking for, but it seems to 
>> correspond to "cut -c", not to "cut -f".  Can it work with delimiters or 
>> only with character counts?
>> 
>> Mike
>> 
>
> x <- "this is a string"
> unlist(strsplit(x," "))[c(1,4)]


Thanks.  I did figure that one out a couple of messages back, but to get 
it do behave like "cut -d' ' -f1,4", I had to add a paste command to 
reassemble the parts:

paste(unlist(strsplit(x," "))[c(1,4)], collapse=" ")

Then I wasn't sure if I could do this to every element of a vector of 
strings without looping -- I have to think not.

Mike