From: Adaikalavan Ramasamy <ramasamy_at_cancer.org.uk>

Date: Sat 01 Oct 2005 - 02:43:41 EST

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat Oct 01 01:48:23 2005

Date: Sat 01 Oct 2005 - 02:43:41 EST

- I am not sure why you want the biased version but here are two ways to do this. Also if you have large enough sample size, it would not matter much.

my.var1 <- function(x) mean( (x - mean(x))^2 ) my.var2 <- function(x) mean( x^2 - mean(x)^2 )

2) Look at quantiles function. Your equation might correspond to one of the types given there.

Regards, Adai

On Fri, 2005-09-30 at 10:46 +0200, Fabrizio Ferri Benedetti wrote:

> Hello everybody (I'm new here)

*>
**> I am looking for 2 specific functions. The first one is a variance
**> formula that does not divide by n-1 (I don't want the unbiased formula,
**> that's it). In case it does not exist, how do I modify the default
**> function code? Yes, a workaround would be to multiply the result by n-1
**> and then divide it by n, but I'd like to use a separate function, if
**> possible.
**>
**> The other function I'm looking for it's a median formula like this one:
**>
**> http://www.faberitius.com/prototipo/gfx/clip_image002_0000.gif
**>
**> Where "Li" is the exact lower limit of the critical interval, "nb" is
**> the number of cases that lie below the critical interval, "nd" the number
**> of cases inside the mentioned interval, and "I" is the range of the
**> interval itself. As you can see this formula calculates the median in
**> categorical structured data.
**>
**> I couldn't find any functions that match the results done by hand... is
**> there a contrib package out there that may help me? Should I program the
**> function on my own?
**>
**> Thanks in advance,
**>
**> Fabrizio Ferri Benedetti
**>
**>
**>
*

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat Oct 01 01:48:23 2005

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