[R] regexpr virtue

[Petr PIKAL]

Thanks

If somebody does not come with more elaborated solution I will adapt 
yours. After strsplit I can get not only 3 but several chunks. If the last 
chunk is every time the one I need then

sapply(strsplit(names(foto),"\\..."), length)
 [1] 2 6 6 6 6 5 5 6 5 3 3 3 3 3 3 3 3 3 3 4 3 3 4 4 3 3 3 3 4 3 3 3 3 3 3 
3 3 3 3 3 3 3 3 3 3 3 3 3 4 3 3 3 3 3 3 3 4 3 3 3 3 3 3 4 4 3 4 3 3
>
gives me number of chunks which I can use for  selection.

Best regards




Jorge Ivan Velez <jorgeivanvelez at gmail.com> napsal dne 29.07.2009 
15:18:33:

> Dear Petr,
> 
> How about this strsplit()ing them up?
> 
> > x
> [1] "X19.2.400v...80"
> > strsplit(x,"\\...")[[1]][3]
> [1] "80"
> 
> HTH,
> 
> Jorge
> 

> On Wed, Jul 29, 2009 at 9:10 AM, Petr PIKAL <petr.pikal at precheza.cz> 
wrote:
> Hi all
> 
> I have got something like that (actually those are column names)
> 
> [51] "X19.2.300b...80"          "X19.2.400v...80" "X19.2.400b...80"
> "X19.2.300v...90"          "X19.2.300b...90"
> [56] "X19.2.400v...90"          "X19.2..400b..90" "X19.2.300v...100"
> "X19.2.300b...100"         "X19.2.400v...100"
> 
> in character vector. I would like to get last n figures from this
> character vector but my regexpr unerstanding is inferior and I did not
> succeed.
> Please, is there anybody who can extract those n digits from end of each
> character string? If there were only 2 digits I could use substr but 
there
> can be one, two or three digits.
> 
> I tried several variations of
> 
> gsub("0:9$", "\\1" ,names(foto)[10])
> 
> but either got whole string or an error.
> 
> Best regards
> Petr
> 
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