[R] Any concept of 'by reference' or 'address of' in R?

[Mark Knecht]

Hi,
   Is there a way to pass the address of a data.frame through a set of
functions in R? I've got some code which is slowing down I think
because my data.frames are getting much larger - now approaching 1
million rows by 50-100 columns - and my functions - originally written
for much smaller data elements are sampling these data.frames a couple
of layers down.

   Before I rewrite them to do the sampling at the top level if there
was a way to pass the address of the data.frame instead of the a copy
of the whole thing then I suspect that would speed things up
significantly.

Thanks,
Mark