On Wed, 18 Jun 2003 [EMAIL PROTECTED] wrote: > I'm attempting to use stepAIC to select a model through a forward procedure. > I want to consider up to all 3-way interactions. > > > > I've attempted to use the following code: > > > > m2.Fwd3way <- stepAIC(m1.Ionly, direction="forward", > > scope=list(upper=~(var1 + var2 + var3 + var4)^3, > lower=~1)) > > > > When I submit this the trace indicates that only 2-way interactions were > considered. Is this due to improper syntax or am I not able to consider > higher order interactions with stepAIC.
Only if all the two-way ones have already been selected. -- Brian D. Ripley, [EMAIL PROTECTED] 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 ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help
