[Rd] vector arguments to if()

[ripley@stats.ox.ac.uk]

The current R-devel now warns about passing vectors of length > 1 to if().
There seem to be a *lot* of such misuses amongst packages, including in
the recommended packages lattice and mgcv.  Since S warns, this is almost
entirely confined to packages originally written for R.

Would package developers please check their packages under R-devel at
their convenience.  I would be interested to hear of any misuses in R
itself: several have come to light but more may be lurking.

-- 
Brian D. Ripley,                  ripley@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 272860 (secr)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595