library(MASS)
?rnegbin
should help you. If your version of S-PLUS does not have MASS, it is not
current and see http://www.stats.ox.ac.uk/pub/MASS4.
On Thu, 29 Apr 2004, Marc Choisy wrote:
> Dear s-plus users,
>
> I have two questions related to the negative binomial distribution.
> Thanks for help.
>
> There are two different ways of looking at the negative binomial
> distribution:
> The first considers 2 parameters: the mean and a clumping parameter.
> The second considers 2 parameters too but which are the number of
> successes and the probability of one success.
> It is the second one which is coded in the s-plus function rnbinom.
> First question:
> I don't have a clear picture of the relations between the two
> expressions.
> Can anybody help me in defining the relation between the parameters of
> the two expressions?
> Second question:
> I intend to simulate a negative binomial distribution of specified mean
> and clumping parameter.
> Can anybody give me some clues to do that with s-plus?
--
Brian D. Ripley, ripley@stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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