[R] finding and opening C source called from R functions.

[Duncan Murdoch]

On 20/12/2010 3:56 PM, Peter Langfelder wrote:
> On Mon, Dec 20, 2010 at 12:48 PM, Chiquoine, Ben<BChiquoine at tiff.org>  wrote:
> >  Hi,
> >
> >  As will soon be very clear I'm an R novice.  I'm trying to better understand the ks.test function in the stats package.  When I look at the source code there are several calls to C functions (for example .C("pkstwo", is.integer(length(x[IND])), p=as.double(x[IND]), as.double(tol), PACKAGE = "stats)$P).  I'm wondering if there is a way to view the source code for the underlying C functions?  I googled a post which said to open ks.c to see the source code but I can't find that file anywhere on my hard drive or on the web.  Any suggestions would be greatly appreciated.
>
> Go to cran.r-project.org, find the package stats, download the tar.gz
> bundle, unpack it (on a linux command line, you can type tar -xvzf
> stats*.tar.gz), then navigate to the directory stats/src and look at
> the source code in the directory.


In many cases that will work, but not in this one:  stats is a base 
package, so there is no tar.gz bundle.

See Uwe Ligges' article in R News on how to find source in general.  It's in

http://cran.r-project.org/doc/Rnews/Rnews_2006-4.pdf

and I think it is all still current.

Duncan Murdoch