R help - Nov 2010 - Adding noise

Hello,
I have some discrete pvalues and I would like to sort them. Then add random
noise so that they are ordered the same way as the original pvalues. Off
course I don't want any pvalues less than 0 or greater than 1. Any ideas on
how to do this in R?

-- 
Thanks,
Jim.

	[[alternative HTML version deleted]]

Why?

-- Bert

(This is not an idle question: What kind of "random noise" do you wish
to add? Normal? Uniform? ...
Once answered, this is trivial to do. However, I expect that if you
explain why you want to do this, the answer will be: don't)



On Tue, Nov 30, 2010 at 11:01 AM, Jim Silverton <jim.silverton at
gmail.com> wrote:
> Hello,
> I have some discrete pvalues and I would like to sort them. Then add random
> noise so that they are ordered the same way as the original pvalues. Off
> course I don't want any pvalues less than 0 or greater than 1. Any
ideas on
> how to do this in R?
>
> --
> Thanks,
> Jim.
>
> ? ? ? ?[[alternative HTML version deleted]]
>
> ______________________________________________
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> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Bert Gunter
Genentech Nonclinical Biostatistics

Jim Silverton <jim.silverton <at> gmail.com> writes:
> 
> Hello,
> I have some discrete pvalues and I would like to sort them. Then add random
> noise so that they are ordered the same way as the original pvalues. Off
> course I don't want any pvalues less than 0 or greater than 1. Any
ideas on
> how to do this in R?
> 

  Are you basically just trying to break ties?

  Something like (completely untested)

eps <- min(diff(c(0,sort(pvaluevector),1)))/2
pvaluevector+runif(length(pvaluevector),min=-eps,max=eps)