[R] how to run stepAIC starting with NULL model?

[Joshua B Robins]

Hello,

I'm trying to figure out how to run the stepAIC function starting with the
NULL model.  I can call the null model (e.g., lm(y ~ NULL)), but using
this object in stepAIC doesn't seem to work.

The objective is to calculate AICc.  This can be done if stepAIC can be
run starting with the NULL model; the (2p(p-1)/(n-p-1))to get AICc would
be added to the final step AIC value. Can anyone suggest how to run
stepAIC beginning with the NULL model, and sequentially adding and
removing variables (essentially a bottom-up approach)?

Thanks,

Josh Robins
School of Fisheries and Ocean Sciences
University of Alaska Fairbanks
Juneau Center
(206) 331-8633
j.robins at uaf.edu
http://students.washington.edu/jbrobins