this is an off-topic, of course! by definition, pdf MUST BE POSITIVE and log function is defined ONLY for positive values. check your pdf code and find out the errors.
regards Patrizio Frederic +------------------------------------------------- | Patrizio Frederic | Research associate in Statistics, | Department of Economics, | University of Modena and Reggio Emilia, | Via Berengario 51, | 41100 Modena, Italy | | tel: +39 059 205 6727 | fax: +39 059 205 6947 | mail: [EMAIL PROTECTED] +------------------------------------------------- 2008/7/23 Zornitsa Luleva <[EMAIL PROTECTED]>: > Hi, > > In order to use the mle2-function, one has to define the likelihood function > itself. As we know, the likelihood function is a sum of the logarithm of > probability density functions (pdf). I have implemented myself the pdfs > that I am using. My problem is, that the pdfs values are negative and I > cann't take the logarithm of them in the log-likelihood function. > > So how can one take the logarithm of negative values of the pdfs? > > Thanks a lot for your advice! > > Zoe > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > 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 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.
