Forward Stepwise regression with stepAIC and step
On Thu, 8 May 2003 pfm401 at lineone.net wrote:
I cannot seem to get the R functions step or stepAIC to perform forward or stepwise regression as I expect.
[...]
wateruse.lm.forward<-stepAIC(wateruse.lm,trace=FALSE,direction="forward")
[...]
In other words no forward procedure has been run (similar results apply if I use direction="step")!!
That's not a valid value for `direction': see the help page.
What am I doing wrong?? Thanks in advance for any help.
You not given a `scope' argument, so there are no variables to add.
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