[R] missing values in step procedure

[Prof Brian Ripley]

On Fri, 7 Oct 2005, Andreas Cordes wrote:

> I have the problem that for the step procedure stops due to missing
> values. There are no options in Step or stepAIC to handle missing
> values. Is there any way to run stepwise modelselection in R in an
> automated way in this case?

Try the hint it gives you, or see the help page (which covers this in a 
warning with an explanation).

[...]

> Error in step(mod2, direction = "back") :
>        number of rows in use has changed: remove missing values?

-- 
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