[R] parsing strings

[Gabor Grothendieck]

strapply in package gsubfn can do that.  The following matches the
indicated regular expression against x and applies the function
given in formula notation (which removes spaces) to each match,
outputting the result as a list:

library(gsubfn)
x <- c("AB10B10", "A10 B5", "AB 10 CD 12", "A10CD2EF3")
strapply(x, "[[:alpha:]] *[[:digit:]]+", ~ gsub(" ", "", x))


For more info, see the gsubfn home page at:
   http://code.google.com/p/gsubfn/
and the various Links there.


On 7/9/07, Drescher, Michael (MNR) <michael.drescher at ontario.ca> wrote:
> Hi All,
>
>
>
> I have strings made up of an unknown number of letters, digits, and
> spaces. Strings always start with one or two letters, and always end
> with one or two digits. A set of letters (one or two letters) is always
> followed by a set of digits (one or two digits), possibly with one or
> more spaces between the sets of letters and digits. A set of letters
> always belongs to the following set of digits and I want to parse the
> strings into these groups. As an example, the strings and the desired
> parsing results could look like this:
>
>
>
> A10B10, desired parsing result: A10 and B10
>
> A10  B5, desired parsing result: A10 and B5
>
> AB 10 CD 12, desired parsing result: AB10 and CD12
>
> A10CD2EF3, desired parsing result: A10, CD2, and EF3
>
>
>
> I assume that it is possible to search a string for letters and digits
> and then break the string where letters are followed by digits, however
> I am a bit clueless about how I could use, e.g., the 'charmatch' or
> 'parse' commands to achieve this.
>
>
>
> Thanks a lot in advance for your help.
>
>
>
> Best, Michael
>
>
>
>
>
>
>
> Michael Drescher
>
> Ontario Forest Research Institute
>
> Ontario Ministry of Natural Resources
>
> 1235 Queen St East
>
> Sault Ste Marie, ON, P6A 2E3
>
> Tel: (705) 946-7406
>
> Fax: (705) 946-2030
>
>
>
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>