I am not sure I fully understand the Qs. There are two phases.
1) The source code is parsed. 2) The parsed code is evaluated. If you run code from source() or a file or the command line, it is parsed and evaluated. However, evaluating a function assignment makes an function object containing the parsed code for the body of a function. Running code a second time is often faster because of caching of memory (in the chip's caches and in RAM ratehr than VM). In S-PLUS there are more layers of caching going on: objects are retrieved from disc and (usually) cached in memory, and memory allocated for objects can be re-used rather than re-allocated. There is no form of pre-compiling to intermediate code on first use (as some Java implementations use), although things like that are in Luke Tierney's long-term plans. I hope that actually answers your questions. On Wed, 25 Jun 2003 [EMAIL PROTECTED] wrote: > Greetings Folks, > > When R code (as entered or read from a courced file) is executed, > is it interpreted from the input form every time having once been > read in, or do subsequent invocations use an "intermediate" > (pre-interpreted) form? > > Or, putting it another way, is the execution of R code faster > second time time round (and later) because the pre-interpretation > has already been done once and for all? > > [And, for seconds, what is the corresponding situation for S-plus?] > > With thanks, > Ted. > > > -------------------------------------------------------------------- > E-Mail: (Ted Harding) <[EMAIL PROTECTED]> > Fax-to-email: +44 (0)870 167 1972 > Date: 25-Jun-03 Time: 10:19:00 > ------------------------------ XFMail ------------------------------ > > ______________________________________________ > [EMAIL PROTECTED] mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help > -- Brian D. Ripley, [EMAIL PROTECTED] 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 ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help
