Re: [Help-gsl] Random numbers within some ranges in the domain using different distributipons?

[Daniel J Farrell]

Hello,

I think gsl_ran_poisson (const gsl_rng * r, double mu) returns the 'k'  
number (i.e. then number of occurrences associated with that  
probability generated by 'r'). This is an educated guess based on the  
fact that p(k,lambda) and you is entering p() and lambda into the  
above function.

You want to sample the poisson distribution in a given range of what?  
Do you have a lambda and a k value? Or do you just have a lambda?

Cheers,

Dan/

On 17 Jun 2008, at 17:44, Mohammad Khaleghi wrote:

> Hello Dan,
>
> Thank you very much for the email and the explaination which is very  
> useful. I might have still some problems. It is maybe due to lack of  
> enough knowledge in statistics :-)
> I saw that most of the functions return double. Do you mean all  
> these are distributed between (0, 1)? Then your solution is in these  
> case perfect. But what should I do in the cases where a long int is  
> returned?
> I copied and pasted an example from the documents, where an unsined  
> int is generated. Almost the same goes for all uniform distributions.
>
>
> — Function: unsigned int gsl_ran_poisson (const gsl_rng * r, double  
> mu)
> This function returns a random integer from the Poisson distribution  
> with mean mu. The probability distribution for Poisson variates is,
> p(k) = {\mu^k \over k!} \exp(-\mu)
> for k >= 0.
>
> Does the above means that the function produces long int values  
> between (0, +inf)?
> If so how can I produce (or get) say long ints between (100, 200)?
> Does it make sense even thinking of something between (-100, 150)?
>
> Thanks a lot
> Mohd
>
> > -----Ursprüngliche Nachricht-----
> > Von: "Daniel J Farrell" <address@hidden>
> > Gesendet: 17.06.08 18:01:50
> > An: Mohammad Khaleghi <address@hidden>
> > CC: address@hidden
> > Betreff: Re: [Help-gsl] Random numbers within some ranges in the  
> > domain using different distributipons?
>
>
> > Hello Mohd,
> >
> > I think you are looking for this function:
> >
> > f(r) = a + (b - a) * r
> >
> > where a is the min value, b is the max values and r is a random  
> > number
> > distributed between 0 and 1 (e.g. use gsl_rng_uniform_pos() to
> > generate r).
> >
> > This come up a lot on the mailing list maybe it should be added to  
> > the
> > library?
> >
> > Cheers,
> >
> > Dan.
> >
> >
> >
> > On 17 Jun 2008, at 16:26, Mohammad Khaleghi wrote:
> >
> > > Hi everybody!
> > >
> > > Could somebody please tell me how to generate random numbers within
> > > some ranges in the domain?
> > > I saw the documentation and did not see anything like setting a min
> > > and max. I mean for a distribution that has a domain (-inf, + inf)
> > > could one set some range (min, max) to sample from? Or it is not
> > > possible with gsl?
> > >
> > > thans, Mohd
> > >
> > > _______________________________________________________________________
> > > EINE FÜR ALLE: die kostenlose WEB.DE-Plattform für Freunde und Deine
> > > Homepage mit eigenem Namen. Jetzt starten! http://unddu.de/?
> > > address@hidden
> > >
> > >
> > >
> > > _______________________________________________
> > > Help-gsl mailing list
> > > address@hidden
> > > http://lists.gnu.org/mailman/listinfo/help-gsl
>
>
> ______________________________________________________________
> Jeden Monat 1 hochkarätiger maxdome-Blockbuster GRATIS!
> Exklusiv für alle WEB.DE Nutzer. http://www.blockbuster.web.de