If S+ has seq(length=...), that would solve any parsing problems. /Henrik On Fri, Feb 12, 2010 at 4:59 PM, William Dunlap <wdun...@tibco.com> wrote: > 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. >
______________________________________________ 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.