Hi Dirk, On Thu, Apr 14, 2011 at 4:59 AM, dirknbr <dirk...@gmail.com> wrote: > Which one is more efficient? > > x2=c() > for (i in 1:length(x)) { > x2=c(x2,func(x[i])) > } > > or > > x2=x > for (i in 1:length(x)) { > x2=func(x[i]) > } > > where func is any function?
This one. Creating a [vector|matrix|dataframe] of its full final size is more efficient than growing it incrementally. But this is likely to be even more efficient, and is shorter and easier to read: x2 <- sapply(x, func) Sarah -- Sarah Goslee http://www.functionaldiversity.org ______________________________________________ R-help@r-project.org 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.