[R] AlgDesign--exact and approximate design

[Dieter Menne]

sun <flyhyena <at> yahoo.com.cn> writes:

.... 
>   Another question is, I want to measure the main effects and at least two 
> interactions, variables are factors, how do I ensure this in  formula, 
> ~.+v1:v2 +v3:v4 ?

I would give something like the following a try (since you did not tell use
where you use the formula, it may not always work).

library(MASS) # Modified from Venables/Ripley
data(quine)
quine.fit = aov(log(Days+2.5)~(Eth+Sex+Age+Lrn)^2,quine)
summary(quine.fit)

Dieter