R help - Jul 2008 - How to pass function argument of same name to internal call?

I ran across this problem when playing with ccf().
Its function call is

 >function (x, y, lag.max = NULL, type = c("correlation",
"covariance"),
     plot = TRUE, na.action = na.fail, ...)

Internally,  ccf() calls plot(), which digs up plot.acf() whose default 
style is type='h' .

I wanted to pass the argument type='l' to the plotting routine, but of 
course I can't put two arguments named "type" into the ccf() call.
I made do with the work-around of writing "myccf," with the argument
for
the acf() call changed to "cortype," but that's ugly.

Is there a way to "escape" an argument so it gets ignored by the main 
function and only gets read by the internally-called function?

thanks for any ideas.
Carl

On 25/07/2008 4:28 PM, Carl Witthoft wrote:
> I ran across this problem when playing with ccf().
> Its function call is
> 
>  >function (x, y, lag.max = NULL, type = c("correlation",
"covariance"),
>      plot = TRUE, na.action = na.fail, ...)
> 
> Internally,  ccf() calls plot(), which digs up plot.acf() whose default 
> style is type='h' .
> 
> I wanted to pass the argument type='l' to the plotting routine, but
of
> course I can't put two arguments named "type" into the ccf()
call.
> I made do with the work-around of writing "myccf," with the
argument for
> the acf() call changed to "cortype," but that's ugly.
> 
> Is there a way to "escape" an argument so it gets ignored by the
main
> function and only gets read by the internally-called function?
No.  You should choose "plot=FALSE", save the result, then call plot()
with your new arg for type.

For example, following the ?ccf example,

 > ccfresult <-  ccf(mdeaths, fdeaths, ylab =
"cross-correlation",
plot=FALSE)
 > plot(ccfresult, type='l')

Duncan Murdoch