RE: [R] R annoyances

From: Liaw, Andy <andy_liaw_at_merck.com>
Date: Fri 20 May 2005 - 23:45:04 EST


> From: Philippe Grosjean
>
> Hello,
> Regarding use of parenthesis, it is true that R is much better with
> f(10) != f[10] != f[[10]], where Matlab is a little
> confusing. Also, in
> Matlab, you can use some functions without (), further adding to the
> confusion (the only example that comes to my mind in R is the
> use of '?'
> as shortcut for help()).
>
> However, there is still a double use of () in R: it is both used for
> enclosing function arguments and for grouping operations. One
> language
> has a syntax that makes a totally unambiguous use of [], () and {} is
> Mathematica: [] is for subscript, {} is for function
> arguments and () is
> for grouping... but Mathematica code is really a pain to
> typeset and read.
>
> So, all in all, I really like the S langage syntax: it is
> very readable
> and reasonably rigid...
>
> Regarding T and F, I took the habit to *always* type them
> TRUE or FALSE.
> Again, very readable and not confusing at all. If T and F as
> equivalent
> to TRUE and FALSE would ever be deprecated and then defunct
> in further
> versions of R, well, I would not complain about it!
>
> The only aspect I don't like is a too loosely use of the dot in
> functions: both in functions names, in object classes and in generic
> functions / methods. Hence, we have for instance: 'data.frame',
> 'help.search' and 'summary.matrix'... just guess which one is
> an object
> class, which one is an ordinary function and which one is a S3 method
> (OK, S4 solves somehow the problem)? It would have been much
> better to
> *reserve* the use of a dot in a function name as a separator
> between the
> name of the generic function and the class to which it applies. Thus,
> 'summary.matrix' would have been correct, but both 'data.frame' and
> 'help.search' should have been spelled differently, perhaps
> 'dataframe'
> and 'helpSearch'. Just a dream... because 'data.frame' will of course
> never be spelled differently!!!

Don't give up to easily: If "_" can be done away as assignment operator, I'd guess anything is fair game...

Andy

> Best,
>
> Philippe Grosjean
>
>
> Jan T. Kim wrote:
> > On Fri, May 20, 2005 at 08:14:24AM -0400, Liaw, Andy wrote:
> >
> >>>From: Robin Hankin
> >>>
> >>>On May 20, 2005, at 11:00 am, Jan T. Kim wrote:
> >>>
> >>>
> >>>>On Thu, May 19, 2005 at 03:10:53PM -0400, John Fox wrote:
> >>>>
> >>>>
> >>>>>Since you can use variables named c, q, or t in any
> event, I don't
> >>>>>see why
> >>>>>the existence of functions with these names is much of an
> >>>
> >>>impediment.
> >>>
> >>>>True, particularly since I'm not too likely to use these
> >>>
> >>>variables for
> >>>
> >>>>(local)
> >>>>functions, and variables of other types don't prevent
> >>>
> >>>functions from
> >>>
> >>>>working.
> >>>>(I thought this was a problem... I must be spoilt by
> >>>
> >>>recently having
> >>>
> >>>>to read
> >>>>too much Matlab code, where parentheses are used to both enclose
> >>>>subscripts and
> >>>>parameter lists, thus rendering subscript expressions and
> function
> >>>>calls
> >>>>syntactically indistinguishable.)
> >>>
> >>>
> >>>Heh, I'm a recovering Matlab user too. This is sooooooooooo true!
> >>>
> >>>In Matlab:
> >>>
> >>>f(10) # function f() evaluated at 10
> >>>f(10) # 10th element of vector f. confusing!!
> >>>
> >>>R uses round brackets in two unrelated ways:
> >>>
> >>> 4*(1+2) --- using "(" and ")" to signify grouping
> >>>f(8) function f() evaluated at 8.
> >>>
> >>>where there is no reason to use the same parenthesis
> symbol for both
> >>>tasks.
> >>
> >>The same is done in Fortran/C/C++/Java/Python and God knows how many
> >>others...
> >
> >
> > And this is different from the subscripting / function call
> ambiguity,
> > as these languages (to the extent I know them) are designed
> such that
> > parentheses for precedence control are syntactically distinguishable
> > from those used for function parameter lists: If the
> opening parenthesis
> > is preceded by an identifier, that identifier is a function name and
> > the parenthesis opens a parameter list.
> >
> > (Python is a somewhat messy case, though, because it uses
> parentheses
> > for tuples too.)
> >
> > Best regards, Jan
>
>
>



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