R help - Dec 2005 - contrasts for lm

I would like estimate a number of contrasts from a one-way ANOVA model.  I see 
that the lm command has a contrasts option, but I can't figure out how to
use
it!  Any help that can be offered would be greatly apreciated.

Here is my model statement:

Model<-lm(log2PM~P+T+P*T)

where P has 16 levels, T(treatment) has 12 levels and I am interested in 
looking at different treatment comparisons.

Thanks!

Ann

Ann Hess <hess <at> stat.colostate.edu> writes:
> 
> Here is my model statement:
> 
> Model<-lm(log2PM~P+T+P*T)
> 
> where P has 16 levels, T(treatment) has 12 levels and I am interested in 
> looking at different treatment comparisons.
With so many levels, you should do something against fishing for error 
accumulation and use simint(simtest) in package multcomp, which can handle lm-
models.

Dieter