Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: st: unexpected -rbinomial- behaviour
From
Jeph Herrin <[email protected]>
To
[email protected]
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<[email protected]> 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<[email protected]> 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/
*
* 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/