R help - Apr 2009 - Function?

Hello all,

I am looking at the one program of the marketing textbook. I understand what
the following function is doing especially the .C command
Can someone help?
If I take off the .C comand will it still run??



drawwc = function(w, mu, y, sigi) {
        .C("draww", w = as.double(w), as.double(mu), as.double(sigi),
            as.integer(length(y)), as.integer(ncol(sigi)), as.integer(y))$w

	[[alternative HTML version deleted]]

Would your blood still circulate if you take
off your heart?

That is, the answer is, "No, that's where the
work is done in the function."  If you want to
understand the computations that function is
doing, then you need to examine the C code
that it is calling.


Patrick Burns
patrick at burns-stat.com
+44 (0)20 8525 0696
http://www.burns-stat.com
(home of "The R Inferno" and "A Guide for the Unwilling S
User")

Jim Silverton wrote:
> Hello all,
>
> I am looking at the one program of the marketing textbook. I understand
what
> the following function is doing especially the .C command
> Can someone help?
> If I take off the .C comand will it still run??
>
>
>
> drawwc = function(w, mu, y, sigi) {
>         .C("draww", w = as.double(w), as.double(mu),
as.double(sigi),
>             as.integer(length(y)), as.integer(ncol(sigi)), as.integer(y))$w
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
>
>