Xin <jasonshi510 <at> hotmail.com> writes: > > Dear All: >
> Then error messga there: initial value in 'vmmin' is not finite > In addition: There were 38 warnings (use warnings() to see them). > > Could you give some advice please? > > Thanks a lot! > > Xin Shi > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help <at> stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > > A little more information (and an informative Subject: line) would help. A reproducible example (let us know how you're calling optim(), and ideally show your data or a subsample of it that produces the same problem --- see the posting guide). A few ideas: - the 'vmmin' error message says that your starting values are giving non-finite results -- this could be because some of your x and y values are negative (which in your could would lead to infinite values). Bottom line: try your objective function with your starting parameter values and see what happens - you could use dnbinom(...,log=TRUE) if you wanted - you may need to be careful with constraining alpha, beta, delta, as you could end up with negative means. ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html