[R] How to specified contrasts in anova (lm)

Bert Gunter bgunter.4567 at gmail.com
Wed Jul 1 23:43:04 CEST 2015


You do not set constraints in R you set contrasts. See the relevant
sections of e.g. Venables and Ripley's MASS book.

?contrasts  ## what else!
?C

for details.

Beyond this, I cannot help.

-- Bert

Bert Gunter

"Data is not information. Information is not knowledge. And knowledge
is certainly not wisdom."
   -- Clifford Stoll


On Wed, Jul 1, 2015 at 2:14 PM, Davide Risso <davide.risso at berkeley.edu> wrote:
> Hi Bert,
>
> I apologize for the HTML. I will pay more attention in the future.
>
> I know that the lm() command of my toy example fits the wrong model
> with a singular design, maybe I shouldn't have included it.
>
> I believe that the model with the additional constraint(s) is not
> garbage. But I don't know how to specify the additional constraints in
> lm() (hence, I believe it's an R question).
>
> I also know that I can fit a mixed effect model, but this was not the
> point of my previous email.
>
> Best,
> davide



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