[R] Looking for .Call functions

[Douglas Bates]

Nathaniel B. Derby wrote:
> Hi,
> 
> In my ongoing quest to track down the source of an error (see message 
> "[R] optim error in arima" above), I find in the cource code for arima0 
> the following:
> 
>     arma0f <- function(p) {
>         par <- as.double(fixed)
>         par[mask] <- p
>         .Call("arma0fa", G, par, PACKAGE = "stats")
>     }
> 
> I would like to know what the function "arma0f" does.  Does the above 
> mean that there is a function called "arma0fa" somewhere in R?  Where is 
> it?  I couldn't find anything in Rinternals.h.

It means that in one of the .c source files in 
$RSRC/src/library/stats/src there will be a C function declared as

SEXP arma0fa(SEXP, SEXP);

(In fact it is declared in ts.h and defined in pacf.c in that directory)