Re: st: unexpected -rbinomial- behaviour

[Jeph Herrin <stata@spandrel.net>]

But it would have been easy enough to trap the endpoints and
return a meaningful (rather than missing) value.


On 9/14/2010 4:34 PM, Tirthankar Chakravarty wrote:
> Jeph,
>
> The Stata function -rbinomial- is not defined for p=0. From
> h rbinomial
> rbinomial(n, p)
>         Domain n:     1 to 1e+11
>         Domain p:     1e-8 to 1-1e-8
>         Range:        0 to n
>
> Your probabilistic statement about the degenerate Binomial
> distribution is correct - the domain of the Binomial distribution is p
> \in [0,1]. My guess would be that the p=/=0 condition is a limitation
> of the simulation algorithm.
>
> T
>
> On Tue, Sep 14, 2010 at 12:54 PM, Jeph Herrin<stata@spandrel.net>  wrote:
> > Am I wrong to expect rbinomial(n,0) = 0?
> >
> > . di rbinomial(10,0)
> > .
> >
> > I would think that if P(success)= 0, then E(successes)=0.
> >
> >
> > Jeph
> >
> >
> > *
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