R devel - Feb 2008 - argument order for Math2 group functions in R 2.6.x (PR#10681)

Dear Ben,

If you take a look at the definition of signif() in R 2.6.1 and, e.g.,
in R 2.5.1 you'll see the source of the problem:

R 2.6.1:
> signif
function (x, digits = 6)  .Primitive("signif")

R 2.5.1:
> signif
function (x, digits = 6) 
.Internal(signif(x, digits))
<environment: namespace:base>
>From ?Primitive:
"The advantage of .Primitive over .Internal functions is the potential
efficiency of argument passing. However, this is done by ignoring
argument names and using positional matching of arguments (unless
arranged differently for specific primitives such as rep), so this is
discouraged for functions of more than one argument."

I guess that in recoding signif() for efficiency, the warning about
multiple arguments was ignored.

Regards,
 John

On Sat,  2 Feb 2008 00:35:03 +0100 (CET)
 ben.hansen at umich.edu wrote:
> Full_Name: Ben Hansen
> Version: 2.6.1
> OS: Windows
> Submission from: (NULL) (66.93.3.101)
> 
> 
> Hi, 
> 
> In R 2.6.0 or 2.6.1 on Windows, I get the following upon opening the
> GUI (no
> previous commands or special settings):
> > signif(digits=4, x=1/3)
> [1] 4
> 
> It seems to be taking 4 to be the "x" argument, the number to be
> rounded. 
> However, my understanding (perhaps mistaken) was that it should
> respond as
> follows:
> > signif(digits=4, x=1/3)
> [1] 0.3333
> 
> (This last is what I get from R 2.5.0 running on the same machine,
> and what I'm
> used to getting using earlier versions.)  Similar things happen with
> round().
> 
> I haven't yet had the opportunity to investigate whether I'd see
the
> same
> behavior on other platforms.  
> 
> Best wishes,
> Ben
> 
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--------------------------------
John Fox, Professor
Department of Sociology
McMaster University
Hamilton, Ontario, Canada
http://socserv.mcmaster.ca/jfox/