[R] power analysis for 2-way anova interaction

[Justin Rhodes]

Dear R-help,

Does anyone have a function that I could use to determine power for 
testing significance of an interaction term in a 2-way ANOVA.  The 
model I am considering has 2 levels in each factor.  I would like to 
be able to input sample size (equal in all groups), MSE, means for 
the 4 groups, and then get power for the 2 main effects and 
interaction term.  It would also be nice to enter the desired power 
for the interaction effect, and then get sample size for the 4 
groups.  Any help or guidance would be greatly appreciated.

Best wishes,

--
Justin S. Rhodes
Department of Psychology
Beckman Institute
Neuroscience Program, Institute for Genomic Biology
University of Illinois
405 N. Mathews Avenue
Urbana, IL 61801

Ph: 217-265-0021
Fax: 217-244-5180
e-mail: jrhodes at uiuc.edu
http://www.psych.uiuc.edu/people/showprofile.php?id=545