[R] na.action in randomForest

[Prof Brian Ripley]

On Sun, 3 Aug 2003, David Parkhurst wrote:

> The help page for randomForest shows na.action=na.fail as a parameter, and
> does not describe other possibilities for na.action.
> 
> I have a regression problem, with about 1000 rows in my data frame, and with
> an NA in occasional predictor variables, in about 5% of rows.  I would like
> to have all rows included in the analysis, to the extent possible.  (That
> seems to be possible in rpart, for example.)  Is it possible to specify that
> rows with a few NA's should be included in the randomForest analysis?  If
> so, how?

What do you want the tree procedure to do with NAs?  Hint: rpart and tree
have two different approaches.

-- 
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