R help - Feb 2003 - assign value to slot of S4 object

Dear list,

I noticed something while assigning a new value to the slot
of an object of class S4.
Apparently(*) this object is copied while the operation
is performed. Is it really wished ?  (or did I miss something ?)

I use R-1.6.2:
> R.version
         _                
platform i686-pc-linux-gnu
arch     i686             
os       linux-gnu        
system   i686, linux-gnu  
status                    
major    1                
minor    6.2              
year     2003             
month    01               
day      10               
language R      



L.


(*): I did 'top' as I heard my machine playing with the swap

Laurent Gautier wrote:
> Dear list,
> 
> I noticed something while assigning a new value to the slot
> of an object of class S4.
> Apparently(*) this object is copied while the operation
> is performed. Is it really wished ?  (or did I miss something ?)
> 
> I use R-1.6.2:
This is a product of the S call-by-value semantics.  There is actually 
an enormous amount of copying which takes place in R (and Splus). 
However, it is only with large objects that this becomes noticable.

Coincidentally John Chambers, Robert Gentleman, Paul Murrell and I were 
discussing exactly this type of issue today.  We are certainly aware 
that there are problems and are looking at potential solutions.

-- 
Ross Ihaka                         Email:  ihaka at stat.auckland.ac.nz
Department of Statistics           Phone:  (64-9) 373-7599 x 85054
University of Auckland             Fax:    (64-9) 373-7018
Private Bag 92019, Auckland
New Zealand