R help - Jan 2007 - need help with debug package

Hi all,     
      I met a problem while using the debug package,  I have the following
program:

mainfun<- function(){
           beta<-1
           result<-subfun(beta+x)
}
                     
subfun<-function(expr){
           y <- eval(expr, envir=list(x=c(1,2)),enclos = parent.frame())
          return(y)
}

I have no problem using this program without calling the debug package.   but
once
I mtrace(subfun),  the debugger can't find all the beta after entering
subfun , and give
the message :     "Error in beta : non-numeric argument to binary
operator"

Is there anyway to get around ?

thanks a lot 
happy new year

I think I have figured out part of the answer,  when I entered a debugger, the
calling environment (parent frame)
refers to the debugger program, instead of the mainfun( ).   But is there anyway
to solve this problem ?

thanks 

----- Original Message -----
From: Tong Wang <wangtong at usc.edu>
Date: Wednesday, January 3, 2007 9:30 pm
Subject: need help with debug package
To: R help <r-help at stat.math.ethz.ch>
> Hi all,     
>      I met a problem while using the debug package,  I have the 
> following program: 
> 
> mainfun<- function(){
>           beta<-1
>           result<-subfun(beta+x)
> }
>                     
> subfun<-function(expr){
>           y <- eval(expr, envir=list(x=c(1,2)),enclos = 
> parent.frame())          return(y)
> }
> 
> I have no problem using this program without calling the debug 
> package.   but once 
> I mtrace(subfun),  the debugger can't find all the beta after 
> entering subfun , and give 
> the message :     "Error in beta : non-numeric argument to binary 
> operator"
> Is there anyway to get around ?
> 
> thanks a lot 
> happy new year
>