Re: [R] [spam] t.test confidence interval

From: Adrian Dusa <dusa.adrian_at_gmail.com>
Date: Sat 16 Apr 2005 - 03:18:57 EST

On 15 Apr 2005 13:53:32 +0200, Peter Dalgaard <p.dalgaard@biostat.ku.dk> wrote:
> Adrian Dusa <dusa.adrian@gmail.com> writes:
>
> > Hi,
> >
> > I'm using R for some undergraduate lectures, reaching the t tests.
> > No matter what conf.level one specifies in the syntax, the output always shows
> > the 95 percent confidence interval.
>
> That's just not true in my version of R.

You're right of course. I just typed "cl" instead of "conf" or "conf.level" and it took the predefined 0.95. Sorry to bothering you.  

> > t.test(extra ~ group, data = sleep, conf=.8)
>
> Welch Two Sample t-test
>
> data: extra by group
> t = -1.8608, df = 17.776, p-value = 0.0794
> alternative hypothesis: true difference in means is not equal to 0
> 80 percent confidence interval:
> -2.7101645 -0.4498355
> sample estimates:
> mean in group 1 mean in group 2
> 0.75 2.33
>
> > Is it possible to alter the function somehow, to report the CL percent
> > confidence interval?
>
> --
> O__ ---- Peter Dalgaard Blegdamsvej 3
> c/ /'_ --- Dept. of Biostatistics 2200 Cph. N
> (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918
> ~~~~~~~~~~ - (p.dalgaard@biostat.ku.dk) FAX: (+45) 35327907
>



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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 Received on Sat Apr 16 03:25:31 2005

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