Thanks for all respondents! I wasn't precise enough, when I enclosed my example. In fact, I need a version which works with all kinds of symbolic data, not only with numbers. So these versions
rle(VECTOR)$values and VECTOR=c(3,2,2,3,4,4,5,5,5,3,3,3,5,1,6,6) NEWVECTOR <- ifelse(VECTOR[-length(VECTOR)]==VECTOR[-1],NA,VECTOR) NEWVECTOR[!is.na(NEWVECTOR)] answered to my needs. I made a test and the first version was 2.5x faster with my data, but both works enough fast. Atte On Wed, 2006-08-16 at 08:58 +0100, Patrick Burns wrote: > I think > > rle(VECTOR)$values > > will get you what you want. > > Patrick Burns > [EMAIL PROTECTED] > +44 (0)20 8525 0696 > http://www.burns-stat.com > (home of S Poetry and "A Guide for the Unwilling S User") > > Atte Tenkanen wrote: > > >Is there some (much) more efficient way to do this? > > > >VECTOR=c(3,2,4,5,5,3,3,5,1,6,6); > >NEWVECTOR=VECTOR[1]; > > > >for(i in 1:(length(VECTOR)-1)) > >{ > > if((identical(VECTOR[i], VECTOR[i+1]))==FALSE){ > > NEWVECTOR=c(NEWVECTOR,VECTOR[i+1])} > >} > > > > > > > >>VECTOR > >> > >> > > [1] 3 2 4 5 5 3 3 5 1 6 6 > > > > > >>NEWVECTOR > >> > >> > >[1] 3 2 4 5 3 5 1 6 > > > >_______________________________ > >Atte Tenkanen > >University of Turku, Finland > > > >______________________________________________ > >R-help@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. > > > > > > > > ______________________________________________ R-help@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.