[R] style question: returning multiple arguments - structure orlist

[fharrell@virginia.edu]

I too am troubled by the computer illiteracy of students
these days.  As an experiment this summer I am having
incoming students who don't know at least one computer
language work through the book "Beginning Programming
for Dummies" by Wallace Wang.  The book teaches programming
through the use of Qbasic (supplied on the CD-rom that
comes with the book) but introduces several other 
languages such as Java.  It appears to be a very good
book and has received good reviews.  My feeling is that
students who know any language such as basic, C, Python,
Perl, Fortran, Java will find it easier to learn S.
Many of my M.S. students have never even seen a DOS
prompt nor have they thought about a "variable".

There is a very good free interactive tutorial for learning
Tk/Tcl where students see explanations, example code,
and a window showing the results of running their own
code (http://www.msen.com/~clif/Tutor2b4.exe). I wish there 
were something like this for other languages, especially S.

-Frank


"Venables, Bill (CMIS, Cleveland)" wrote:
> 
> I see Thomas has already nailed this one, so it becomes a non-issue.
> Nevertheless I feel moved to say I think the idea would have been a step in
> the wrong direction in the first place.  It comes from a desire to make R
> behave "a bit more like matlab" and that is ultimately unhelpful.
> 
> Having tried to teach generations of students how to use the system (S-PLUS,
> but it could equally well have been R) I can say the most difficult people
> to teach it to are those you have to "convert" from a long history of
> expertise in another system.  Trying to make R behave like the previous
> system (SAS, Stata, SPSS, Matlab, APL, ....), as they are invariably
> determined to do, is ultimately futile, but you, the teacher, find yourself
> doing all sorts of hand-stands and cartwheels to meet these people half-way.
> 
> It doesn't work.  Trust me.  In the end it *really* *doesn't* *work*.
> Seriously.
> 
> I'm not sure how we can best help these people, either, but I'm working on
> it.  It comes as a dreadful shock for them to find that R is not just SAS,
> or Matlab, or APL, or... in some foreign notation but a genuinely different
> system.  They have real trouble expanding their mental outlook just enough
> to handle the fact that such a thing is even possible.
> 
> In Adelaide where I taught with S-PLUS for about a decade I had no real
> problems in getting the students on board.  (Some, like David Smith, even
> went on to have distinguished careers in the game.)  But I got nowhere with
> my fellow staff members, some of whom just never got over Matlab, or SAS, or
> ...
> 
> Sigh.
> 
> Bill Venables.
> 
> -----Original Message-----
> From: Peter Dalgaard BSA [mailto:p.dalgaard at biostat.ku.dk]
> Sent: Sunday, 29 July 2001 7:24 AM
> To: vogels at cmu.edu
> Cc: rhelp
> Subject: Re: [R] style question: returning multiple arguments -
> structure orlist
> 
> "Thomas J Vogels" <tov at ece.cmu.edu> writes:
> 
> > Hi,
> >
> > you also have the option of "throwing out" the third result by setting it
> to
> > NULL (taking your LIST option)?
> >
> > > f <- function() {
> > >   ...
> > >   list(x=x,y=y,z=z)
> > > }
> > > res <- f()
> > > names(jj)
> > [1] "x" "y" "z"
> > > res$z <- NULL
> > > names(res)
> > [1] "x" "y"
> >
> > and then work with res (res$x and res$y)?
> 
> A little summer exercise: Can one write a list assignment function,
> i.e. "list<-" so that
> 
> list(a,b,c) <- f()
> 
> would be equivalent to
> 
> r <- f()
> a <- r[[1]]
> b <- r[[2]]
> c <- r[[3]]
> 
> Even better, do something useful with named list elements. (And what
> are the odds of finding that this is really an exercise hidden
> somewhere in a book by Venables and Ripley?)
> 
> --
>    O__  ---- Peter Dalgaard             Blegdamsvej 3
>   c/ /'_ --- Dept. of Biostatistics     2200 Cph. N
>  (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
> ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907
> -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.
> -.-
> r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
> Send "info", "help", or "[un]subscribe"
> (in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch
> _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._.
> _._
> -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
> r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
> Send "info", "help", or "[un]subscribe"
> (in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch
> _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._

-- 
Frank E Harrell Jr              Prof. of Biostatistics & Statistics
Div. of Biostatistics & Epidem. Dept. of Health Evaluation Sciences
U. Virginia School of Medicine  http://hesweb1.med.virginia.edu/biostat
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._