R strsplit and vectorization
        Posted  
        
            by James
        on Stack Overflow
        
        See other posts from Stack Overflow
        
            or by James
        
        
        
        Published on 2010-06-16T15:14:31Z
        Indexed on 
            2010/06/16
            15:22 UTC
        
        
        Read the original article
        Hit count: 623
        
When creating functions that use strsplit, vector inputs do not behave as desired, and sapply needs to be used. This is due to the list output that strsplit produces. Is there a way to vectorize the process - that is, the function produces the correct element in the list for each of the elements of the input?
For example, to count the lengths of words in a character vector:
words <- c("a","quick","brown","fox")
> length(strsplit(words,""))
[1] 4 # The number of words (length of the list)
> length(strsplit(words,"")[[1]])
[1] 1 # The length of the first word only
> sapply(words,function (x) length(strsplit(x,"")[[1]]))
a quick brown   fox 
1     5     5     3 
# Success, but potentially very slow
Ideally, something like length(strsplit(words,"")[[.]]) where . is interpreted as the being the relevant part of the input vector.
© Stack Overflow or respective owner