On Tue, 24 Aug 2010, Hadley Wickham wrote:
Hi all,
If a package suggests another package in its description, you can
check it at runtime with requires. How do you do check if a package
Well, not really as requires() can give an error, at least until
2.12.0 is out. So you need to wrap it in a try/tryCatch construct.
is available without loading it, if you only want to access one
function in the package namespace.
You could use try/tryCatch on pkg::fun (which is what you need to do
with require). It is difficult (and would be fragile since the
details of metadata are definitely subject to change without notice)
to ascertain what a namespace will contain/export without loading it.
Thanks,
Hadley
--
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
--
Brian D. Ripley, rip...@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
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
