[R] Multivariate Contrasts

[Michael Friendly]

On 10/6/2010 6:07 PM, Ali S wrote:
> Hi,
> I am interested in running multivariate contrasts from manova. Here is the code I have currently for a one-way Manova. I would like to run multivariate contrasts for the Year factor.
> Thanks!
> #Reduced model
> t14m1<-manova(as.matrix(t14c[,4:10])~t14c$Year)
>
>
> #get multivariate results
> summary.manova(t14m1)
> summary.manova(t14m1,test="Wilks")
>
>
> #Anova in the car package can run Type III tests
> Anova(t14m1,type="III")
> Anova(t14m1,type="III",test="Wilks")

In general, if Year is a factor, you may get what you want simply by 
assigning to
contrasts(t14c$Year) <-
See ?contrasts

See also linearHypothesis in the car package and, e.g., 
demo("bees.contrasts") plus
vignette("HE-examples"),vignette("repeated") in the heplots package
(version heplots_0.9-5 )