[R] Beginner's question about t.test()

[Pramote Khuwijitjaru]

Dear Peter Dalgaard

Thank you very much.



>From: <p.dalgaard at biostat.ku.dk>

>
>"Pramote Khuwijitjaru" <kmote at hotmail.com> writes:
>
> > Dear All,
> > I am doing some exercise in statistics textbook on comparison of two
> > experimental means. Is it possible to use t.test() do t-test when I
> > have only two means, sample size, two standard deviations ? (no raw
> > data).
>
>Only if you "cheat".
>
>fake.data <- function(n,mu,sigma) mu + sigma*scale(rnorm(n))
>x1 <- fake.data(20, 12.345, .678)
>x2 <- fake.data(20, 13.456, .789)
>mean(x1)
>sd(x1)
>mean(x2)
>sd(x2)
>
>t.test(x1,x2)
>--
>    O__  ---- Peter Dalgaard             Blegdamsvej 3
>   c/ /'_ --- Dept. of Biostatistics     2200 Cph. N
>  (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
>~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907