Re: [Rd] bug in power.t.test( ) (PR#7245)

From: <ligges_at_statistik.uni-dortmund.de>
Date: Sat 25 Sep 2004 - 01:12:17 EST


Martin Maechler wrote:

>>>>>>"UweL" == Uwe Ligges <ligges@statistik.uni-dortmund.de>
>>>>>>    on Fri, 24 Sep 2004 08:43:56 +0200 (CEST) writes:

>
>
> UweL> mai@ms.uky.edu wrote:
> >> Full_Name: Mai Zhou Version: 1.9.1 OS: Win XP
> >> Professional Submission from: (NULL) (12.222.227.93)
> >>
> >>
> >>
> >>> power.t.test(n=25, delta=0.1, sig.level=1.1,
> >>> strict=TRUE, type="one.sample")
> >>
> >>
> >> One-sample t test power calculation
> >>
> >> n = 25 delta = 0.1 sd = 1 sig.level = 1.1 power =
> >> 1.088311 alternative = two.sided
> >>
> >> ### power can never be over one! Of course, sig.level
> >> should not take value > 1 ### either. ### Possible
> >> solution: A check in the input to truncate sig.level into
> >> [0, 1]??
>
> UweL> Well, an error (or at least warning) message seems to
> UweL> be more appropriate rather than silently changing some
> UweL> values, e.g. somehwere at the top of the functions
> UweL> body:
>
> UweL> if(any(sig.level < 0 | sig.level > 1))
> UweL> stop("sig.level must be in [0,1]")
>
> yes, in principle;
> thank you, Uwe!
>
> Since sig.level can also be NULL

Yes.

> (which works with the way you
> constructed the test - on purpose?), I'd use the test a bit
> differently.
>
> BTW, did you know that e.g., sig.level or delta can be *vectors*

Yes, hence the "|" rather than "||".

Uwe

> giving vectorized results - at least in some cases...
> That will hopefully leed to more documentation / code updates,
> but not for 2.0.0 I presume.
>
> Martin Maechler



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https://stat.ethz.ch/mailman/listinfo/r-devel Received on Sat Sep 25 01:21:22 2004

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