From afinley at stat.umn.edu  Tue Apr  4 16:42:30 2006
From: afinley at stat.umn.edu (Andrew Finley)
Date: Tue, 04 Apr 2006 09:42:30 -0500
Subject: [Rd] change function's formals default values
In-Reply-To: <Pine.LNX.4.64.0604040714090.26620@homer22.u.washington.edu>
References: <1144114759.15762.3.camel@populus.fr.umn.edu>
	<Pine.LNX.4.64.0604040714090.26620@homer22.u.washington.edu>
Message-ID: <1144161750.18246.7.camel@populus.fr.umn.edu>

Hi Thomas, 

Thanks for the note. I'm not sure about a lot of things. Setting the
formal defaults then calling the function seem straight forward.  I just
assumed it would be like setting list values, or the C equivalent of
calling formals(fn)<-list(a=1, b=3).

Following your suggestion, I can get the names of the parameters used in
this user defined function, but am not sure how to do what you are
suggesting. For instance, how do I call the function after I use setVar.
Could you point me to an example?

Thanks again!

Andrew

On Tue, 2006-04-04 at 07:21 -0700, Thomas Lumley wrote:
> On Mon, 3 Apr 2006, Andrew Finley wrote:
> 
> > Hello,
> >
> > I'm passing a user defined function into my c code. Once this function
> > is in my c code, I'd like to iteratively change the values associated
> > with the parameters defined in the function's formal list then evaluate
> > the function using these newly set defaults (i.e., using lang1(fn)).
> >
> > My question is, how do I simply change the value associated with each
> > parameter in this function's formal list. I have messed around with the
> > SET_FORMAL function but can't figure out how to change these values.
> >
> 
> <recoils in horror>
> 
> Are you *sure* you want to do this?  It seems that you should be able to 
> use lexical scope to store this information in variables rather than 
> default arguments and then you can use setVar to change the variables 
> rather than changing the formals.
> 
>  	-thomas
> 
> Thomas Lumley			Assoc. Professor, Biostatistics
> tlumley at u.washington.edu	University of Washington, Seattle
> 
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[Rd] change function's formals default values
Andrew Finley