I am trying to calculate n, using power.t.test
power.t.test(n=NULL,delta=delta, sd=sigmaEins,
sig.level= alpha, power=power, type=c("two.sample"),
alternative=c("two.sided"))
The values of the parameter are read in from a file.
I have no idea what the error message means.
--- Peter Dalgaard <[EMAIL PROTECTED]> wrote:
> forkusam <[EMAIL PROTECTED]> writes:
>
> > Hi,
> > Can someone please tell me what such an error
> message
> > could mean. i.e where a problem must have arised.
> >
> > Error in uniroot(function(n) eval(p.body) - power,
> > c(2, 1e+07)) :
> > f() values at end points not of opposite
> sign
>
> Looks like the innards of one of the power
> calculations, finding n to
> achieve a given power. You'd likely get an error
> like that if the
> power is not between 0 and 1, but how about telling
> us what you were
> trying to do?
>
> --
> O__ ---- Peter Dalgaard Blegdamsvej
> 3
> c/ /'_ --- Dept. of Biostatistics 2200 Cph. N
>
> (*) \(*) -- University of Copenhagen Denmark
> Ph: (+45) 35327918
> ~~~~~~~~~~ - ([EMAIL PROTECTED])
> FAX: (+45) 35327907
=====
=====================
Sylvie B. Forkusam
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Tel: (0049)-06221/346913
Mobile: 0179-6816276
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