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From |
Jeph Herrin <stata@spandrel.net> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: unexpected -rbinomial- behaviour |

Date |
Wed, 15 Sep 2010 12:12:42 -0400 |

I meant only the endpoints on p; eg rbinomial(1e+10,0) should in theory always return 0. On 9/15/2010 11:25 AM, Steve Samuels wrote:

-- " But it would have been easy enough to trap the endpoints and return a meaningful (rather than missing) value." Jeph, I don't think its so simple. What value would you report for cases like this: di rbinomial(1e+10,1e-9) // n x p = 10 . Steve On Tue, Sep 14, 2010 at 5:26 PM, Jeph Herrin<stata@spandrel.net> wrote: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 * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/* * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/* * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

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**References**:**st: unexpected -rbinomial- behaviour***From:*Jeph Herrin <stata@spandrel.net>

**Re: st: unexpected -rbinomial- behaviour***From:*Tirthankar Chakravarty <tirthankar.chakravarty@gmail.com>

**Re: st: unexpected -rbinomial- behaviour***From:*Jeph Herrin <stata@spandrel.net>

**Re: st: unexpected -rbinomial- behaviour***From:*Steve Samuels <sjsamuels@gmail.com>

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