Beware of adding a constant... the magnitude of the constant used can have an outsized impact on the answer obtained. See e.g. https://gist.github.com/jdnewmil/99301a88de702ad2fcbaef33326b08b4
On January 19, 2023 3:49:29 AM PST, peter dalgaard <pda...@gmail.com> wrote: >Not necessarily homework, Bert. There's a generic issue with MLE and rounded >data, in that gamma densities may be 0 at the boundary but small numbers are >represented as 0, making the log-likelihood -Inf. > >The cleanest way out is to switch to a discretized distribution in the >likelihood, so that instead of log(dgamma(0,...)) you use log(pgamma(.005,..) >- pgamma(0,...)) == pgamma(.005,..., log=TRUE). (For data rounded to nearest >.01, that is). Cruder techniques would be to just add, like, .0025 to all the >zeros. > >-pd > >> On 10 Jan 2023, at 18:42 , Bert Gunter <bgunter.4...@gmail.com> wrote: >> >> Is this homework? This list has a no-homework policy. >> >> >> -- Bert >> >> On Tue, Jan 10, 2023 at 8:13 AM Nyasha <kahuninyasha13...@gmail.com> wrote: >>> >>> Please how can one go about this one? I don't know how to go about it. >>> >>> [[alternative HTML version deleted]] >>> >>> ______________________________________________ >>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >>> https://stat.ethz.ch/mailman/listinfo/r-help >>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html >>> and provide commented, minimal, self-contained, reproducible code. >> >> ______________________________________________ >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. > -- Sent from my phone. Please excuse my brevity. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
