Hi, mle caused me some confusion too.
Anyway, first of all, your x should not contain 0, so make it, let say, (1:10)/10. Secondly, f should not be the density, but -log(density), so in your case it should be f <-function(theta) -sum(log(theta) + (theta-1)*log(x)) and finally you must specify a start value, i.e. your call should be mle(f,start=list(thetha=1)) --- On Thu, 19/6/08, Manli Yan <[EMAIL PROTECTED]> wrote: > From: Manli Yan <[EMAIL PROTECTED]> > Subject: [R] try to find the MLE of a function > To: "r-help@r-project.org" <r-help@r-project.org> > Received: Thursday, 19 June, 2008, 1:49 PM > Hi everyone: > I have a density function > f(x|theta)=theta*x^(theta-1),where > 0<x<1,0<theta<infinite > > I want to pratice on R to find the MLE of this > function,here is my code: > x <- (0:10)/10 > f<-function(theta) prod(theta*x^(theta-1)) > mle(f) > and r gave me :Error in eval(expr, envir, enclos) : > argument is missing, > with no default > > what mistake I just made?and how to add a constraint of > theta>0 in my > function. > > Great thanks for your time~ > > [[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.
