[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

śr., 28 lut 2024 o 19:42 Jacek Kownacki <samsungx1298 using gmail.com> napisał(a):

> 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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