Re: [R] Anova Test

From: Petr PIKAL <petr.pikal_at_precheza.cz>
Date: Tue, 15 May 2007 17:48:08 +0200


r-help-bounces_at_stat.math.ethz.ch napsal dne 15.05.2007 17:32:35:

>
> Thank you Guys.
>
> Let say that from Test1 to control i have multiple data
>
> Tester
> Test1 Test2 Test3 Test4 Control
> 20 25 15 10 17
> . . . . .
> . . . . .
> 40 20 15 35 45
>
> Is this the method i need to use?

Better is to use stacked format.

value testno
20 t1
... t1

40     t1
25     t2
...    t2
20     t2

...

then

anova(lm(value~testno, data=yourdata)) will give you anova table. However be carefull to keep testno as a factor. You could also consult some introductory literature which can be find on CRAN, especially about data manipulation and linear models. Maindonald, Verzani or Faraway is a good starting choice.

Regards
Petr

>
> anova(lm(......this is where i am not sure how to put them.
>
> is this something to do with anova(lm(dependent~independent*independent,
> data=name)
>
> if they are all independent, how do i put them together?
>
> thanks.
>
>
> Ben Bolker-2 wrote:
> >
> >
> >
> > CrazyJoe <keizer_61 <at> hotmail.com> writes:
> >
> >>
> >> I am very new to R. I am trying to perform an Anova Test and see if
it
> >> differs or not.
> >>
> >> Basically, i have 4 tests and 1 control.
> >>
> >> Tester
> >> Test1 Test2 Test3 Test4 Control
> >> 20 25 15 10 17
> >>
> >
> > You can't make any inferences with the data you have here.
> > You need to have multiple observations per treatment!
> > See the examples for ?lm .
> >
> > ______________________________________________
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> > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
> >
>
> --
> View this message in context:
http://www.nabble.com/Anova-Test-tf3758829.html#a10625154
> Sent from the R help mailing list archive at Nabble.com.
>
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https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Received on Tue 15 May 2007 - 15:53:42 GMT

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