[R] S4 : setGeneric for classical methods
cgenolin at u-paris10.fr
cgenolin at u-paris10.fr
Mon Jul 28 15:53:13 CEST 2008
Martin Maechler <maechler at stat.math.ethz.ch> a écrit :
>>>>>> "CG" == Christophe Genolini <cgenolin at u-paris10.fr>
>>>>>> on Sun, 27 Jul 2008 09:27:34 +0200 writes:
>
> CG> Martin Maechler <maechler at stat.math.ethz.ch> a écrit :
> >>>>>>> "CG" == Christophe Genolini <cgenolin at u-paris10.fr>
> >>>>>>> on Sat, 26 Jul 2008 12:12:12 +0200 writes:
> >>
> CG> Martin Maechler <maechler at stat.math.ethz.ch> a écrit :
> >> >>>>>>> "CG" == Christophe Genolini <cgenolin at u-paris10.fr>
> >> >>>>>>> on Tue, 22 Jul 2008 19:04:37 +0200 writes:
> >> >>
> CG> Prof Brian Ripley <ripley at stats.ox.ac.uk> a écrit :
> >> >> >> On Tue, 22 Jul 2008, cgenolin at u-paris10.fr wrote:
> >> >> >>
> >> >> >>> Hi the list (well, half of the list, only the one who
> >> >> >>> are not on holidays...)
> >> >> >>>
> >> >> >>> I am trying to make an S4 package. When I run it on a
> >> >> >>> console, everything seems ok. When I run R CMD check, I
> >> >> >>> got an error --- 8<
> >> >> >>> ----------------------
> >> >> >>> Error in setMethod("plot", "ClassX", function(x, y) { :
> >> >> >>> no existing definition for function "plot" --- 8<
> >> >> >>> ----------------------
> >> >> >>>
> >> >> >>> If I add
> >> >> >>> setGeneric("plot",function(x,y,...){standardGeneric("plot")})
> >> >> >>> in my code, then everything is OK.
> >> >> >>>
> >> >> >>> This is a surprise for me since I taught that we do not
> >> >> >>> need to redefine as generic the function that are
> >> >> >>> already generic, like "plot". Am I wrong ?
> >> >> >>
> >> >> >> Yes. And do read the error message. It says
> >> >> >>
> >> >> >> no existing definition for function "plot"
> >> >> >>
> >> >> >> so this is not if the function is S3 or S4 generic, but
> >> >> >> that no such function is visible.
> >> >> >>
> >> >> >> Looks like you forgot to declare a dependence on (or
> >> >> >> import) package graphics.
> >> >>
> CG> I would have forgot if I knew that I have to declare
> CG> such a dependence... Do we have to declare all the
> CG> depence to all the package ? To base ? To stats ?
> >> >>
> >> >> not to base, but to all other packages (since R can be loaded
> >> >> without any packages but base).
> >> >>
> CG> I thaught that the package that are include in R when we
> CG> start it had not to be include.
> >> >>
> >> >> You thought wrongly, and all our documentation mentions that you
> >> >> need to use 'Depends:' correctly (and 'Imports(..)' in
> >> >> NAMESPACE if you make use of one).
> >> >>
> >> >> {and please strongly note the correct spelling of "thought" !}
> >> >>
> >> >> Martin
> >>
> CG> I correct DESCRIPTION and NAMESPACE adding Depends and import.
> CG> But I still get the message :
> >>
> CG> checking for missing documentation entries ... WARNING
> CG> Undocumented S4 methods:
> CG> generic 'plot' and siglist 'ClassX'
> >>
> CG> I can't find what is wrong...
> >>
> >> well, it's a message about *documentation*
> >> and therefore not related to DESCRIPTION
> >> and not much related to NAMESPACE.
> >>
> >> It tells you that you don't have correct documentation for the
> >> plot method for ClassX.
>
>
> CG> What if I don't want to document this method? I did not put ClassX in
> CG> the export, I do not want the user to acces to it.
> CG> I want :
>
> CG> plot,ClassX-method -> private
> CG> ClassY-class -> public
> CG> plot,ClassY-method -> public
>
> CG> Is it possible ?
>
> Yes, it is.
> Excuse me not having read your previous posting in full detail.
>
> So what you see is a warning in 'R CMD check' that is a so
> called "false positive", i.e. warning in a case it should not.
>
> Indeed, we have to acknowledge that the "R CMD check"ing code
> in the context of "S4 + NAMESPACE" has not been perfect
> recently... and the above is a good test case for improving the
> "checking code".
>
> BTW: I have recently started to look into using a few dummy
> packages as part of the R-internal 'make check' checks.
> Consequently, I'd be quite happy if you could provide (me or
> R-devel) with the full packS4_0.5.tar.gz example package
> {and maybe other versions of that}.
>
> Merci, Christophe, for your perseverance!
>
> Martin
Thanks for your explanation.
About "packS4", I am curently writing a tutorial on S4 packaging (I am
adding a part on "S4 package" to the tutorial "A (Not So) Short
Introduction to S4" already on the net).
packS4 comes as an illustrative example for this tutorial. The tutorial
is almost over, I just need to understand what is wrong with my tests
files and I post it. Do you want it now (with bugs in the tests
directory) or do you want the final version ?
Christophe
>
>
> CG> Christophe
>
> --> "Writing R Extensions",
> >> section 2.1.3 'Documenting S4 classes and methods'
> >>
> >> Regards,
> >> Martin
> >>
> CG> ----- DESCRIPTION ----- Package: packS4
> CG> Type: Package
> CG> Title: Toy example of S4 package
> CG> Version: 0.5
> CG> Date: 2008-07-22
> CG> Author: Christophe Genolini / INSERM U669
> CG> Maintainer: <genolini at u-paris10.fr>
> CG> Description: Package built to illustration package
> >> construction with S4
> CG> License: GPL (>=2)
> CG> LazyLoad: yes
> CG> Depends: methods, graphics
> CG> Collate: global.R ClassX.R ClassY.R ClassX-ClassY.R ClassZ.R
> >>
> >>
> CG> ------ NAMESPACE ------
> CG> export(
> CG> "classZ",
> CG> "functionClassicA"
> CG> )
> CG> exportMethods(
> CG> "getZ1",
> CG> "setZ1<-",
> CG> "publicA",
> CG> "plot"
> CG> )
> CG> exportClasses(
> CG> "ClassY",
> CG> "ClassZ"
> CG> )
> >>
> CG> import(graphics)
> >>
> CG> Christophe
> >>
> >>
> >>
> >>
> CG> ----------------------------------------------------------------
> CG> Ce message a ete envoye par IMP, grace a l'Universite Paris 10
> >> Nanterre
> >>
> >>
> >>
>
> CG> ______________________________________________
> CG> R-help at r-project.org mailing list
> CG> https://stat.ethz.ch/mailman/listinfo/r-help
> CG> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> CG> and provide commented, minimal, self-contained, reproducible code.
>
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