[R] Regular expression help

[Georges Monette]

How about this (I'm showing it as a pipe because it's easier to read 
that way):

library(magrittr)
"f 147/1315/587 2820/1320/587 3624/1321/587 1852/1322/587" %>%
   strsplit(' ') %>%
   unlist %>%
   sub('^[^/]*/*','',.) %>%
   sub('^[^/]*/*','',.) %>%
   paste(collapse = ' ')

Georges Monette

-- 
Georges Monette, PhD P.Stat.(SSC) | Associate Professor. Faculty of Science, Department of Mathematics & Statistics | North 626 Ross Building | York University | 4700 Keele Street, Toronto, ON M3J 1P3 | Telephone: 416-736-5250 | Fax: 416-736-5757 | E-Mail: georges at yorku.ca


On 2017-10-09 11:02 AM, Duncan Murdoch wrote:
> I have a file containing "words" like
>
>
> a
>
> a/b
>
> a/b/c
>
> where there may be multiple words on a line (separated by spaces).  
> The a, b, and c strings can contain non-space, non-slash characters. 
> I'd like to use gsub() to extract the c strings (which should be empty 
> if there are none).
>
> A real example is
>
> "f 147/1315/587 2820/1320/587 3624/1321/587 1852/1322/587"
>
> which I'd like to transform to
>
> " 587 587 587 587"
>
> Another real example is
>
> "f 1067 28680 24462"
>
> which should transform to "   ".
>
> I've tried a few different regexprs, but am unable to find a way to 
> say "transform words by deleting everything up to and including the 
> 2nd slash" when there might be zero, one or two slashes.  Any 
> suggestions?
>
> Duncan Murdoch
>
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