Rscript and default packages

On Sep 3, 2009, at 13:52 , Romain Francois wrote:

On 09/03/2009 05:23 PM, Duncan Murdoch wrote:

On 03/09/2009 9:53 AM, Romain Francois wrote:

Hi,

Is is possible to embed inside an R script, the name of the default
packages to be loaded when the script is invoked with Rscript.

I know about the --default-packages argument, but I was wondering  
if
there was a mechanism to embed this information within the script  
itself

I don't understand what you'd want here that you don't get with  
attach()
or require(). Why does it matter if they are default?

Duncan Murdoch

Sorry for being vague. I am more interested in not loading some  
packages:

$ time Rscript  -e "#"

real	0m0.224s
user	0m0.188s
sys	0m0.032s


$ time Rscript --default-packages="base" -e "#"

real	0m0.067s
user	0m0.033s
sys	0m0.016s


$ time r -e "#"

real	0m0.039s
user	0m0.032s
sys	0m0.006s

This is related to the "How to ship R scripts with R packages"  
thread. I'd like for example to ship a script that I know only  
requires the "base" package. How would I specify this from within  
the script.

Well, what's wrong with:

#!/usr/bin/Rscript --default-packages=base

ginaz:sandbox$ time ./scr

real	0m0.045s
user	0m0.027s
sys	0m0.017s

.. as opposed to

#!/usr/bin/Rscript --default-packages=base

ginaz:sandbox$ time ./scr

real	0m0.201s
user	0m0.166s
sys	0m0.034s

Cheers,
Simon