[R] variable scope

[Fred J.]

--- Duncan Murdoch <dmurdoch at pair.com> wrote:
> On Fri, 26 Mar 2004 21:34:21 -0800 (PST), you wrote:
> 
> >Hello
> >
> >getdata <- function(p){
> >  fname <- NULL; dl <- list(NULL)#build the
> sturcture
> >  dt <- read.csv(file.path(d,i),header=F)  #data
> frame
> >  ret <- builddl(dt,s) #where "s" is a string
> >}
> >
> >how can I get this following function to use fname
> and
> >dl from the above function without passing them
> down
> >the chain?
> >
> >builddl <- function(q,s){
> >  fname <- c(fname,s)
> >  dl <- list( dl, q)
> >}
> 
> The normal way would be to define builddl() within
> getdata(), i.e.
> 
> getdata <- function(p){
>   builddl <- function(q,s){
>     fname <- c(fname,s)
>     dl <- list( dl, q) 
>   }
>   fname <- NULL; dl <- list(NULL)#build the
> sturcture
>   dt <- read.csv(file.path(d,i),header=F)  #data

the only problem with this method is that the debug
package$mtrace will not step into the sub.fun builddl
becuase it will treat it as one line statement. hummm
> frame
>   ret <- builddl(dt,s) #where "s" is a string
> }
> 
> Duncan Murdoch