In R, is there a way to remove a common word from a vector of characters?

Question

In R, I currently have a vector of characters such as:

character.vec
> "File1.mat"      "File2.mat"       "File3.mat"        "File4.mat"

I was wondering if there were any functions to call on character.vec so that I can get something like:

"File1"      "File2"       "File3"        "File4"

instead. Thanks!

It appears that you just want to strip off the file extensions, but I suspect your logic is something else. What is your logic? — Tim Biegeleisen, Mar 28 '18 at 01:39

James · Accepted Answer · 2018-03-28T02:01:00.137

I think you're after:

> sub("\\.mat", "", character.vec)
[1] "File1" "File2" "File3" "File4"

You need the \\ before the . to distinguish it from its use in regular expressions as matching any character (https://www.rdocumentation.org/packages/base/versions/3.4.3/topics/regex).

More generally, if you wanted to replace everything in a string from the last period to the end, you could use:

sub("\\.[^\\.]*?$", "", character.vec)

score 2 · Answer 2 · answered Mar 28 '18 at 01:51

There's also a built in way for parsing filenames without extensions:

> library(tools) # in base R, shouldn't need to load
> test <- c("File1.mat","File2.mat","File3.mat","File4.mat") 
> tools::file_path_sans_ext(test)
[1] "File1" "File2" "File3" "File4"

In R, is there a way to remove a common word from a vector of characters?

2 Answers2