[R] Testing significance in a design with unequal but proportional sample sizes

[Prof Brian Ripley]

On Fri, 5 Mar 2004, pallier wrote:

...

> Actually, the different types of main effects defined above just 
> correspond to different
> contrasts on the cell means. So if there is an easy solution to compute 
> arbitrary contrasts
> on the cell means in a factorial design, this could an approach to this
> question. (Anyone?)

There are at least three such ways.  ?contrasts (for the assignment
function contrasts<-)  and ?C, as well as the contrasts= argument to aov 
(the function you were discussing ...).

-- 
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