[R] Loops and memory

[Prof Brian Ripley]

On Tue, 6 May 2003, R A F wrote:

> Hi, this question is meant to be a bit vague, since I'm really not
> familiar with all the issues involved.  It's also a problem that I
> think many would have encountered and would have useful suggestions.
> 
> According to MASS, 2nd ed., p. 158, "A major issue is that S is
> designed to be able to back out from uncompleted calculations, so
> that memory used in intermediate calculations is retained until
> they are committed."  The end of the paragraph says that recent
> versions of S are better.  And I seem to remember that R is also
> better with memory management.

That was written in 1996, when rich people had 64Mb of RAM and teaching
labs often had 4 or 8Mb (and R would not run much of the code in the book
and crashed quite often).  Take a look at `S Programming' for a less
ancient view.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595