The next version of S+ will have seq_len in it. Currently the CSAN package Rcompat contains it.
Parsing the name seq_len can be a problem, since S+ 8.1 still allows the use of the underscore for assignment (it warns about its use, but allows it). Either parse your code file in R mode by calling set.parse.mode("R") or use backticks, `seq_len`. By the way, a long time ago I proposed the syntax n +: m to mean the increasing sequence from n up to m, returning integer(0) if m<n, but no one cared for the syntax. (n -: m would make the analogous decreasing sequence.) It would make things like 1 +: n work like seq_len(n) but also made things like curMax <- x[1] for(i in 2 +: length(x)) if (x[i] > curMax) curMax <- x[i] a little simpler to write so it works when length(x)==1. Currently you might write that for statement as if (length(x)>1) for(i in 2:length(x)) or for(i in as.integer(seq(from=2L, length=length(x)-1))) # seq(len=) -> numeric, not integer or for(i in 1L + seq_len(length(x)-1)) Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com > -----Original Message----- > From: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] On Behalf Of Peter Ehlers > Sent: Friday, February 12, 2010 3:48 AM > To: r-help@r-project.org > Subject: Re: [R] Using seq_len() vs 1:n] > > Pat Burns makes a good point. -Peter > > -------- Original Message -------- > Subject: Re: [R] Using seq_len() vs 1:n > Date: Fri, 12 Feb 2010 09:01:20 +0000 > From: Patrick Burns <pbu...@pburns.seanet.com> > To: Peter Ehlers <ehl...@ucalgary.ca> > References: <4b746aef.10...@ucalgary.ca> > > If you want your code to be compatible with > S+, then 'seq_len' isn't going to work. > > On 11/02/2010 20:39, Peter Ehlers wrote: > > R-people, > > > > Duncan Murdoch's response in > > > > https://stat.ethz.ch/pipermail/r-help/2010-February/227869.html > > > > reminded me of something I had been meaning to ask. > > > > A while ago I started using > > > > for(i in seq_len(v)) {....} > > > > in preference to > > > > for(i in 1:n) {....} > > > > Duncan's post shows that if n can be zero, there is > > an advantage to using seq_len. > > Is there ever a *dis*advantage? > > > > Peter Ehlers > > University of Calgary > > > > ______________________________________________ > > 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. > > > > -- > Patrick Burns > pbu...@pburns.seanet.com > http://www.burns-stat.com > (home of 'The R Inferno' and 'A Guide for the Unwilling S User') > > -- > Peter Ehlers > University of Calgary > > ______________________________________________ > 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. > ______________________________________________ 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.