Joaquim,
you have to write your own function that takes the data and the index,
which is passed to it by boot().
try this ...
x2 <- c(2, 3, 4, 5, 6, 5, 4, 5, 6, 5, 4, 5, 6, 5, 7, 2, 3, 4, 3,
4, 3, 5, 6, 7, 5)
mean.boot <- function(x, i) mean(x[i])
b1 <-boot(x2, mean.boot, 999)
b1
Cheers
Andrew
> Dear All,
>
> I tried to use the boot function, provided in the boot package, in such a
> simple task as to create a bootstrap distribution of the mean of a vector
x.
> I wrote:
>
> b <- boot(x, mean, R=200)
>
> Well, it doesn't work. I suspect it has something to do with what is
called
> "second argument" of the "statistic" in the help page
of boot. What is the
> second argument of mean? I don't understand. The whole description in
the
> documentation about this "second argument" is somewaht cryptic
and
> confusing.
>
> Will someone please help me?
>
> Sincerely,
>
> J. Marques de S?
>
> jmsa at fe.up.pt
>
> ______________________________________________
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> PLEASE do read the posting guide
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> and provide commented, minimal, self-contained, reproducible code.
--
Andrew Robinson
Department of Mathematics and Statistics Tel: +61-3-8344-9763
University of Melbourne, VIC 3010 Australia Fax: +61-3-8344-4599
http://www.ms.unimelb.edu.au/~andrewpr
http://blogs.mbs.edu/fishing-in-the-bay/