R help - Jun 2007 - locked environment and inheritance

Hi,

I have a S3 package with namespace called "myS3Pkg". Inside my package
I would like to create
a S4 class which extends (adds 2 slots) another S4 class from some other
package. The class
should be created in "myPkg" environment (and not global environment).

Using:


setClass("myS4class", representation("otherS4class", mydata
= "numeric"),
where = topenv())

I get:


Error in assign(classMetaName(Class), def, where) :


        cannot add bindings to a locked environment




I understand the fact that after "myPkg" is loaded, its namespace is
sealed, but I was hoping to find a way around it.

I would appreciate any comment on this.

thank you.





       
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johan Faux <johanfaux at yahoo.com> writes:
> Hi,
>
> I have a S3 package with namespace called "myS3Pkg". Inside my
package
> I would like to create a S4 class which extends (adds 2 slots) another
> S4 class from some other package. The class should be created in
> "myPkg" environment (and not global environment).
>
> Using:
>
>
> setClass("myS4class", representation("otherS4class",
mydata > "numeric"), where = topenv())
have you tried just omitting the where argument?  Classes will get
defined in the package environment and I think that's what you want.

+ seth
-- 
Seth Falcon | Computational Biology | Fred Hutchinson Cancer Research Center
http://bioconductor.org

Thanks for your reply.

Experimenting a little further, I was able to learn a bit more and find what is
the real problem of mine what the real question is.

I could create my S4 extended class by adding these two lines in my namespace
file
importClassesFrom(Matrix,Matrix)
importClassesFrom(Matrix,dMatrix)

and then creating my new class in another R file

library(Matrix)
setClass("myMatClass",
representation("dMatrix",myslot="numeric"))


which creates the new S4 class when my package is loaded. 

The problem is that I would like to create the class inside a function of mine:

createMyS4Class() {
    library(Matrix)

    setClass("myMatClass",
representation("dMatrix",myslot="numeric"))
}

so that, at some point (after my package is loaded ), I can do something like:

if (cond)
    createMyS4Class()

Now, I understand that at this point, my package environment is locked.  So the
question become:
Is there any way that I can unlock my package environment, create my new S4
class and lock it back or something?

Please let me know if that makes sense ? 
I appreciate your comments.





-importing the foreign S4 class in my  namespace file

----- Original Message ----
From: Seth Falcon <sfalcon@fhcrc.org>
To: johan Faux <johanfaux@yahoo.com>
Cc: r-help@stat.math.ethz.ch
Sent: Monday, June 4, 2007 2:40:21 PM
Subject: Re: [R] locked environment and inheritance

johan Faux <johanfaux@yahoo.com> writes:
> Hi,
>
> I have a S3 package with namespace called "myS3Pkg". Inside my
package
> I would like to create a S4 class which extends (adds 2 slots) another
> S4 class from some other package. The class should be created in
> "myPkg" environment (and not global environment).
>
> Using:
>
>
> setClass("myS4class", representation("otherS4class",
mydata > "numeric"), where = topenv())
have you tried just omitting the where argument?  Classes will get
defined in the package environment and I think that's what you want.

+ seth
-- 
Seth Falcon | Computational Biology | Fred Hutchinson Cancer Research Center
http://bioconductor.org








 
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