R help - Oct 2010 - Writing R code for "moments"

Dear Experts,

If I have a vector of numbers x. 

(1) How can I write R code to compute the moments around zero of order one
to four?

(2) How can I write R code to compute the moments around the mean of order
one to four?

Thank you very much!
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July <iowncup <at> gmail.com> writes:
> (1) How can I write R code to compute the moments around zero of order one
> to four?
> 
> (2) How can I write R code to compute the moments around the mean of order
> one to four?

  Just checking: is this homework?  Why do you need to do this?
What is your input: a list of numbers, a function that encodes
a probability distribution, ... ?  If the former, there are
existing skew and kurtosis functions out there
(install.packages("sos"); library("sos");
findFn("kurtosis")),
and it's pretty easy to do something like mean(x), mean(x^2),
mean(x^3), mean(x^4) for the non-central moments ...

Hi July,

You might want to check out the "moments" package. It has a couple
functions, "all.moments()" and "moment()" that will compute
these for
you.

By the way, "RSeek.org" is a great place to find packages like this; I
searched for "sample moments" and clicked on the "functions"
tab to
find this.

HTH,
Ethan

On Fri, Oct 8, 2010 at 1:19 AM, July <iowncup at gmail.com>
wrote:
>
> Dear Experts,
>
> If I have a vector of numbers x.
>
> (1) How can I write R code to compute the moments around zero of order one
> to four?
>
> (2) How can I write R code to compute the moments around the mean of order
> one to four?
>
> Thank you very much!
> --
> View this message in context:
http://r.789695.n4.nabble.com/Writing-R-code-for-moments-tp2967946p2967946.html
> Sent from the R help mailing list archive at Nabble.com.
>
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