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From |
Maarten Buis <maartenlbuis@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: gamma |

Date |
Thu, 11 Oct 2012 15:00:29 +0200 |

There is a difference between the gamma function (http://en.wikipedia.org/wiki/Gamma_function) and the gamma distribution (http://en.wikipedia.org/wiki/Gamma_distribution). -gamma- used the gamma distribution in a survival analysis context, what you seem to want is the gamma function. Nick already told you how to get that, so there is no need to go back and forth between Stata and R. -- Maarten On Thu, Oct 11, 2012 at 2:45 PM, Jason Rosenberg <RSNJAS002@myuct.ac.za> wrote: > When I type in: help gamma, I get: > > Out-of-date command > As of Stata 8.0, the cox, weibull[het], lnormal[het], gamma[het], llogist, > llogistic[het], ereg[het], and gompertz[het] commands are out of date. > The replacement for cox is stcox. > The replacement for weibull[het], lnormal[het], gamma[het], llogist, > llogistic[het], ereg[het], and gompertz[het] is streg. > I read through those but to no avail. > > In any case I used R to do the gamma part. > If possible could you tell how to run this for a continuous variable in place of the 6, I did it for discreet variables, as in: > egen number = seq() > then: > gen prob=(v/gamma(alpha/v))*(beta^(2*alpha)/(number+11.2)^(alpha+1))*exp(-(beta^2/(number+11.2))^v) > but I need a curve instead of a simple scatter plot. If you could direct me to the relevant help files that would suffice.. > > > ________________________________________ > From: owner-statalist@hsphsun2.harvard.edu [owner-statalist@hsphsun2.harvard.edu] on behalf of Nick Cox [njcoxstata@gmail.com] > Sent: Thursday, October 11, 2012 12:31 PM > To: statalist@hsphsun2.harvard.edu > Subject: Re: st: gamma > > There is no function -gamma()-, largely I suspect because its values > become very big. > > There is a function -lngamma()-, so you would need -exp(lngamma())-. > > Almost all of this can be established by looking at the help for -functions-. > > Nick > > On Thu, Oct 11, 2012 at 1:25 PM, Jason Rosenberg <RSNJAS002@myuct.ac.za> wrote: >> hi >> I an attempting to put this equation into stata: >> >> gen prob=(v/gamma(alpha/v))*(beta^(2*alpha)/(6+11.2)^(alpha+1))*exp(-(beta^2/(6+11.2))^v) >> where v, alpha, and beta are predefined my the user >> and I get : >> unknown function gamma() >> >> Is there another syntax I should know for gamma? >> ### UNIVERSITY OF CAPE TOWN This e-mail is subject to the UCT ICT policies and e-mail disclaimer published on our website at http://www.uct.ac.za/about/policies/emaildisclaimer/ or obtainable from +27 21 650 9111. This e-mail is intended only for the person(s) to whom it is addressed. If the e-mail has reached you in error, please notify the author. If you are not the intended recipient of the e-mail you may not use, disclose, copy, redirect or print the content. If this e-mail is not related to the business of UCT it is sent by the sender in the sender's individual capacity. ### >> >> >> * >> * For searches and help try: >> * http://www.stata.com/help.cgi?search >> * http://www.stata.com/support/faqs/resources/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/faqs/resources/statalist-faq/ > * http://www.ats.ucla.edu/stat/stata/ > ### UNIVERSITY OF CAPE TOWN This e-mail is subject to the UCT ICT policies and e-mail disclaimer published on our website at http://www.uct.ac.za/about/policies/emaildisclaimer/ or obtainable from +27 21 650 9111. This e-mail is intended only for the person(s) to whom it is addressed. If the e-mail has reached you in error, please notify the author. If you are not the intended recipient of the e-mail you may not use, disclose, copy, redirect or print the content. If this e-mail is not related to the business of UCT it is sent by the sender in the sender's individual capacity. ### > > > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/faqs/resources/statalist-faq/ > * http://www.ats.ucla.edu/stat/stata/ -- --------------------------------- Maarten L. Buis WZB Reichpietschufer 50 10785 Berlin Germany http://www.maartenbuis.nl --------------------------------- * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/

**References**:**st: gamma***From:*Jason Rosenberg <RSNJAS002@myuct.ac.za>

**Re: st: gamma***From:*Nick Cox <njcoxstata@gmail.com>

**RE: st: gamma***From:*Jason Rosenberg <RSNJAS002@myuct.ac.za>

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