[R] Replace split with regex for speed ?

[Henrique Dallazuanna]

Try this:

 sub("\\.(\\d+)$", "\\1", ts)


On Thu, Mar 17, 2011 at 11:01 PM, rivercode <aquanyc at gmail.com> wrote:
>
> Have timestamp in format HH:MM:SS.MMM.UUU and need to remove the last "." so
> it is in format HH:MM:SS.MMMUUU.
>
> What is the fastest way to do this, since it has to be repeated on millions
> of rows. Should I use regex ?
>
> Currently doing it with a string split, which is slow:
>
>  >head(ts)
> [1]  09:30:00.000.245  09:30:00.000.256  09:30:00.000.633  09:30:00.001.309
> 09:30:00.003.635  09:30:00.026.370
>
>
>  ts = strsplit(ts, ".", fixed = TRUE)
>  ts=lapply(ts, function(x) { paste(x[1], ".", x[2], x[3], sep="") } )  #
> Remove last . from timestamp, from HH:MM:SS.MMM.UUU to HH:MM:SS.MMMUUU
>  ts = unlist(ts)
>
> Thanks,
> Chris
>
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-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O