[R] finding method file?

[Roger D. Peng]

The `summary' function (i.e. the generic) is defined in the "base" package, the 
source code of which is in src/library/base/R in the R source tree (try the file 
"summary.R").  There are also a number of methods defined there.

The source code is not in the R *installation*, since the code for the 
base/recommended packages is loaded via lazy-loaded databases.  When looking for 
source code, it's good to check the sources, not the installation.

The latest release source is at 
http://cran.us.r-project.org/src/base/R-2/R-2.2.1.tar.gz

-roger

ivo welch wrote:
> dear R wizards:
> 
> I am trying to determine how to determine (no further recursion) where
> a built-in function is defined.  In particular, I have decided I am
> going to add sd() to the existing basic summary function, rather than
> try to rewrite my own summary() function from scratch.
> 
> So, I just installed R-2.2.1 (via gentoo; eventually I will figure out
> how to get atlas/sse/sse2 working on amd64, too!  PS: [a] how can I
> determine whether a running S installation uses sse2, sse, and atlas? 
> [b] does atlas use sse2; [c] are there now modern graphics processor
> routines that might speed up R, too?  ok, all of these are irrelevant
> sidequestions).
> 
> then, I did a
> 
>    > summary
>     [not informative about which file it is defined in]
> 
> ok, easy.  Just grep.  back on the unix line,
> 
>    # grep -r '1st Qu' /usr/lib/R
> 
> which should look for this fairly unique string.  to my surprise, it
> was only found in R-intro.html.
> 
> so, how would I go about looking for where R defines functions?  or
> has this becomes so deeply wired into fortran/C in later versions that
> it can no longer be changed?
> 
> help/advice as always appreciated.
> 
> sincerely,
> 
> /ivo welch
> 
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-- 
Roger D. Peng  |  http://www.biostat.jhsph.edu/~rpeng/