[BioC] How to generate count data with desired overdispersion

[Davis McCarthy]

Hi Joao

Have you tried the ?rnbinom function? The "size" argument to rbinom() determines the extent of overdispersion. Note that this "size" is the inverse of the dispersion parameter as used in the edgeR package (i.e. size = 1/ dispersion ). So I would consider size=1 to be high overdispersion, size=5 to be medium and size > 100 to be low overdispersion.

Hope that helps get you started.

Cheers
Davis
 


On Jul 6, 2011, at 1:22 AM, João Barbosa wrote:

> Hi,
> 
> Basically the question is already made: I would like to generate count data
> with high/medium/low oversdispersion... Can someone help me?
> 
> Thanks a lot!
> 
> -- 
> João Moura
> 
> 	[[alternative HTML version deleted]]
> 
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------------------------------------------------------------------------
Davis J McCarthy
Research Technician
Bioinformatics Division
Walter and Eliza Hall Institute of Medical Research
1G Royal Parade, Parkville, Vic 3052, Australia
dmccarthy at wehi.edu.au
http://www.wehi.edu.au




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