R devel - Nov 2009 - Registered S3 methods not found: Documentation bug or anomaly in function update or ... ?

Dear expeRts,

I recently asked for help on an issue with S3 methods for lm. The issue 
was (in DoE.base 0.9-4)
that function update from package stats would return an error whenever 
DoE.base was loaded,
complaining that lm.default was not found
(e.g.
require(DoE.base)
swiss.lm <- lm(Fertility~Education+Examination, swiss)
upd.swiss.lm <- update(swiss.lm, .~.-Examination)
).

In version 0.9-4 of DoE.base, I had followed the recommendations of 
Section 1.6.2 of "Writing R
extensions", exporting the generic function lm and registering the 
methods (lm.design and lm.default)
with S3method but not separately exporting them in the namespace file.
Not having received help fast, I decided to try to explicitly export the 
method functions
lm.design and lm.default. This did in fact remove the
issue with not finding lm.default when using function update, and I have 
uploaded this fixed version
as 0.9-5.

Is it generally advisable to also export the method functions (i.e. 
should section
1.6.2 of "Writing R extensions" be revised) ? Or is there an anomaly
in
function update ? Or ...?
Explanations are appreciated.

Thanks and regards, Ulrike

-- 

***********************************************
* Ulrike Groemping *
* BHT Berlin - University of Applied Sciences *
***********************************************
* +49 (30) 39404863 (Home Office) *
* +49 (30) 4504 5127 (BHT) *
***********************************************
* http://prof.tfh-berlin.de/groemping *
* groemping at bht-berlin.de *

Well,

 > swiss.lm

Call:
lm.default(formula = Fertility ~ Education + Examination, data = swiss)


That means the call is registered as lm.default and update calls that 
one (and it is hidden in your namespace.

You can fix it on your side so that the call is registered as lm(.....) 
in the lm object.

Anyway, I think it is a bit dangerous to redefine lm() the way you did it.

Best wishes,
Uwe






Ulrike Gr?mping wrote:
> Dear expeRts,
> 
> I recently asked for help on an issue with S3 methods for lm. The issue 
> was (in DoE.base 0.9-4)
> that function update from package stats would return an error whenever 
> DoE.base was loaded,
> complaining that lm.default was not found
> (e.g.
> require(DoE.base)
> swiss.lm <- lm(Fertility~Education+Examination, swiss)
> upd.swiss.lm <- update(swiss.lm, .~.-Examination)
> ).
> 
> In version 0.9-4 of DoE.base, I had followed the recommendations of 
> Section 1.6.2 of "Writing R
> extensions", exporting the generic function lm and registering the 
> methods (lm.design and lm.default)
> with S3method but not separately exporting them in the namespace file.
> Not having received help fast, I decided to try to explicitly export the 
> method functions
> lm.design and lm.default. This did in fact remove the
> issue with not finding lm.default when using function update, and I have 
> uploaded this fixed version
> as 0.9-5.
> 
> Is it generally advisable to also export the method functions (i.e. 
> should section
> 1.6.2 of "Writing R extensions" be revised) ? Or is there an
anomaly in
> function update ? Or ...?
> Explanations are appreciated.
> 
> Thanks and regards, Ulrike
>