> -----Original Message----- > From: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] On Behalf Of Paul Johnson > Sent: Friday, March 19, 2010 1:44 PM > To: R-help > Subject: [R] Does S inherit the enhancements in R language? > > I don't know anybody who has S-plus these days, but I expect some of > you might, and perhaps you won't mind telling me something.
TIBCO Software Inc takes care of S+ these days. We do try to avoid gratuitous incompatibilities between R and S+. When we implement new functionality we check to see if R has the same thing and will use R's name for it if so. When R does something a bit differently we sometimes ask if it was intended and might even suggest a change. As for the underscore, a few years ago we introduced a mode="R" or "Splus" argument to parse() whose main effect is how the underscore is treated (assignment operator in Splus mode and part of a name in R mode). In the latest release, the parser emits a deprecation warning whenever it sees the underscore while in Splus mode (the user cannot turn off this warning). Soon it will not be an assignment operator. S+ does not now have namespaces. However, your rep example is mainly a problem when your rep is the name of a function, not the name of a nonfunction, as they are looked up differently. Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com > > I'm working on my presentation about R for the general audience. As I > survey the suggestions from this list about that project, I find > myself wondering whether S-plus benefits from R. Does S-plus syntax > change like R's does. I can take code for S and run it through R, but > if I took some R code to an S-plus system, would it work? > > Example 1. _, <-, = > > The old S documents I find emphasize assigment with "_". > > When I started with R, that was deprecated, then forbidden. "_" was > not allowed in file names, now it is. It was absolutely necessary to > use <-. = caused errors. Around the time of R-2.1 or so, it became > possible to run R code that has = for assignments. It's not encouraged > by R core team, but = is allowed. > > Does S+ now accept either > > <- > > or > > = > > ? > > For that matter, in S+ is it now forbidden to use underscore for > assignment, as it is in R? > > Example 2. Semicolons now discouraged in R code. > > We used to require ; to end commands. > > Now the R parser is smart enough to spot line breaks and interpret > them accordingly. R's been that way for as long as I can remember, but > I think the ; was required in earliest R releases. > > I rather liked the definitive ; at the end of every command. That > looks right to me, probably because of my SAS and C background. > > Would S+ have a panic attack? > > Example 3. Namespace. Does S-plus get better as R does? > > Years ago, I was modeling US Democrats and Republicans and I created > an indicator variable called "rep". regression models would not work > after that because the rep function had been blocked. It was very > frustrating to me. > Professor Ripley spotted the error and posed a message called "Don't > use the names of R functions as variable names" > http://www.mail-archive.com/r-h...@stat.math.ethz.ch/msg11585.html. > > After that, I was terrified that any name I used might conflict with a > built in R function name. > > Last month, i saw a student here with a political model and he used > rep as a variable in a regression model, it seemed to work just fine. > I surmise that the rise in usage of namespaces in R packages accounts > for that? > > I'm sorry if this is too OT for r-help. > > pj > -- > Paul E. Johnson > Professor, Political Science > 1541 Lilac Lane, Room 504 > University of Kansas > > ______________________________________________ > 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.
