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Re: st: unexpected -rbinomial- behaviour


From   Tirthankar Chakravarty <tirthankar.chakravarty@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: unexpected -rbinomial- behaviour
Date   Tue, 14 Sep 2010 13:34:15 -0700

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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>



-- 
To every ω-consistent recursive class κ of formulae there correspond
recursive class signs r, such that neither v Gen r nor Neg(v Gen r)
belongs to Flg(κ) (where v is the free variable of r).

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