[R] eliminating string from a char vector

[Marc Schwartz]

on 06/21/2008 09:19 PM milton ruser wrote:
> Hi there,
> 
> I have a list of filenames like
> 
> a<-c("file1.dbf", "file32.dbf", "myfile_temp.dbf")
> 
> and I would like to remove the ".dbf" string from all records and obtain
> somethink like
> 
> file1
> file32
> myfile_temp
> 
> Thanks in advance,
> 
> miltinho
> brazil

As is usually the case with R, there are several approaches:

 > sub("\\.dbf", "", a)
[1] "file1"       "file32"      "myfile_temp"

 > sapply(strsplit(a, "\\."), "[", 1)
[1] "file1"       "file32"      "myfile_temp"

 > substr(a, 1, nchar(a) - 4)
[1] "file1"       "file32"      "myfile_temp"


My personal preference would be the first.

See ?sub, ?strsplit, ?sapply, ?substr and ?nchar for more information.

As an aside, if you should need to manipulate complete file paths to 
extract the file name, see ?basename

HTH,

Marc Schwartz