[R] Interactions in regression

[Jacek Kownacki]

Hi Rolf,
No it is not.
I don't know to which question did you want to respond ?
I desribed everything in my first email and  attached links from SO with
pictures included, which are quite understandable.

Cheers,
Jacek

wt., 27 lut 2024 o 02:29 Rolf Turner <rolfturner using posteo.net> napisał(a):

>
> I have no real idea what you are trying to do, but if a table is
> what you want, you can probably get it using the table() function.
> Or, more likely, the xtabs() function.
>
> Using your example from an earlier post (adjusted to make it
> comprehensible to the human mind):
>
> set.seed(1000)
> time      <- factor(rep(c("Pre","Post"),each=200))
> treatment <- factor(rep(rep(c("Control","Treatment"),each=100),2))
> mu        <- rep(rep(1:2,each=100),2)
> response  <- rnorm(400,mean=mu)
> xmpldata  <- data.frame(time=time,treatment=treatment,response)
> mod       <- lm(response~time*treatment,data=xmpldata)
> yhat      <- fitted(mod)
> xtb       <- with(xmpldata,xtabs(yhat ~ time+treatment))
>
> print(xtb)
>
> >       treatment
> > time     Control Treatment
> >   Post  94.10501 201.99112
> >   Pre  101.63792 210.04248
>
> Is that (something like) what you want?
>
> cheers,
>
> Rolf Turner
>
> P.S. You said:  "I usually use GUI software".  Now *there* lies your
> problem.  A GUI is a black box that removes all control over what is
> going on, from your hands.
>
> R. T.
>
>
>
>
> --
> Honorary Research Fellow
> Department of Statistics
> University of Auckland
> Stats. Dep't. (secretaries) phone:
>          +64-9-373-7599 ext. 89622
> Home phone: +64-9-480-4619
>

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