From ripley at stats.ox.ac.uk  Tue Apr 23 15:01:40 2013
From: ripley at stats.ox.ac.uk (Prof Brian Ripley)
Date: Tue, 23 Apr 2013 14:01:40 +0100
Subject: [Rd] Help: Where can I find the code for 'C_Cdqrls'?
In-Reply-To: <000e01ce3ff5$1ec9eb90$5c5dc2b0$@gmail.com>
References: <000e01ce3ff5$1ec9eb90$5c5dc2b0$@gmail.com>
Message-ID: <51768634.8040805@stats.ox.ac.uk>

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



[Rd] Help: Where can I find the code for 'C_Cdqrls'?
Prof Brian Ripley