R devel - Apr 2013 - Help: Where can I find the code for 'C_Cdqrls'?

Dear all,

                I’m not sure if it is O.K. to ask this question here.

                But where can I find the code for the function ‘C_Cdqrls’ which
is called by the R function ‘lsfit‘.

                Thank you all.

                Sorry for being naïve if so.

--------------------

Ziqiang Zhao

2013-04-23

 


	[[alternative HTML version deleted]]

On 23.04.2013 09:35, ??? wrote:
> Dear all,
>
>                  I???m not sure if it is O.K. to ask this question here.
>
>                  But where can I find the code for the function
???C_Cdqrls??? which is called by the R function ???lsfit???.
Look into the R sources:

grepping for dqrls shows the following relevant files:


./src/appl/dqrls.f:      subroutine 
dqrls(x,n,p,y,ny,tol,b,rsd,qty,k,jpvt,qraux,work)
./src/include/R_ext/Applic.h:void F77_NAME(dqrls)(double *x, int *n, int 
*p, double *y, int *ny,
./src/library/stats/src/init.c:    CALLDEF(Cdqrls, 3),
./src/library/stats/src/lm.c:    z <- .Fortran("dqrls",
./src/library/stats/src/lm.c:SEXP Cdqrls(SEXP x, SEXP y, SEXP tol)
./src/library/stats/src/lm.c:    F77_CALL(dqrls)(REAL(qr), &n, &p, 
REAL(y), &ny, &rtol,
./src/library/stats/src/statsR.h:SEXP Cdqrls(SEXP x, SEXP y, SEXP tol);


Best,
Uwe Ligges

>
>                  Thank you all.
>
>                  Sorry for being na??ve if so.
>
> --------------------
>
> Ziqiang Zhao
>
> 2013-04-23
>
>
>
>
> 	[[alternative HTML version deleted]]
>
>
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>

First, it is not a function.  It is an R object in the stats namespace 
and you can look at it like any other object:

 > stats:::C_Cdqrls
$name
[1] "Cdqrls"

$address
<pointer: 0x7f8483499750>
attr(,"class")
[1] "RegisteredNativeSymbol"

$dll
DLL name: stats
Filename: /Users/ripley/R/R-devel/library/stats/libs/stats.so
Dynamic lookup: FALSE

$numParameters
[1] 3

attr(,"class")
[1] "CallRoutine"      "NativeSymbolInfo"

That tells you it is invoking a C function called Cdqrls: you can search 
from that in the sources for package stats.  In fact it is in 
src/library/stats/src/lm.c .

You would know to look in the stats namespace since you found this in a 
function from that namespace.

Generally R's own code uses the convention of object C_foo for C entry 
point foo and F_bar for Fortran entry point bar (but there are 
exceptions, more so in R < 3.0.0).


On 23/04/2013 08:35, ??? wrote:
> Dear all,
>
>                  I???m not sure if it is O.K. to ask this question here.
>
>                  But where can I find the code for the function
???C_Cdqrls??? which is called by the R function ???lsfit???.
>
>                  Thank you all.
>
>                  Sorry for being na??ve if so.
>
> --------------------
>
> Ziqiang Zhao
>
> 2013-04-23
>
>
>
>
> 	[[alternative HTML version deleted]]
>
>
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595