[Rd] Re: [R] Is k equivalent to k:k ?

Martin Maechler maechler at stat.math.ethz.ch
Mon Dec 13 10:21:11 CET 2004

>>>>> "RichOK" == Richard A O'Keefe <ok at cs.otago.ac.nz>
>>>>>     on Mon, 13 Dec 2004 10:56:48 +1300 (NZDT) writes:

    RichOK> I asked:
    >> In this discussion of seq(), can anyone explain to me
    >> _why_ seq(to=n) and seq(length=3) have different types?

    RichOK> Martin Maechler <maechler at stat.math.ethz.ch>
    RichOK> replied: well, the explantion isn't hard: look at
    RichOK> seq.default :-)
    RichOK> That's the "efficient cause", I was after the "final
    RichOK> cause".  That is, I wasn't asking "what is it about
    RichOK> the system which MAKES this happen" but "why does
    RichOK> anyone WANT this to happen"?

sure, I did understand you quite well -- I was trying to joke
and used the " :-) " to point the joking ..

    MM> 	now if that really makes your *life* simpler,
    MM> what does that tell us about your life ;-) :-)

{ even more " :-) "  !! }
    RichOK> It tells you I am revising someone else's e-book
    RichOK> about S to describe R.  The cleaner R is, the easier
    RichOK> that part of my life gets.

of course, and actually I do agree for my life too, 
since as you may believe, parts of my life *are* influenced by R.

Apologize for my unsuccessful attempts to joking..

    RichOK> seq: from, to, by, length[.out], along[.with]

    MM> 	I'm about to fix this (documentation, not code).
    RichOK> Please don't.  There's a lot of text out there:
    RichOK> tutorials, textbooks, S on-inline documentation, &c
    RichOK> which states over and over again that the arguments
    RichOK> are 'along' and 'with'.  

you meant
     'along' and 'length'

yes. And everyone can continue to use the abbreviated form as
I'm sure nobody will introduce a 'seq' method that uses
*multiple* argument names starting with "along" or "length"
(such that the partial argument name matching could become a problem).

    RichOK> Change the documentation, and people will start
    RichOK> writing length.out, and will that port to S-Plus?
    RichOK> (Serious question: I don't know.)

yes, as Peter has confirmed already.

Seriously, I think we wouldn't even have started using the ugly
".with" or ".out" appendices, wouldn't it have been for S-plus
compatibility {and Peter has also given the explanation why there
*had* been a good reason for these appendices in the past}.


More information about the R-devel mailing list