Thanks Bert, I increased the number of iterations: M_model <- nls(weight ~ alpha + beta*exp(gamma*week),control=nls.control(maxiter=200), weightData, start = c(alpha = 0.0, beta = 1, gamma = 0.2), trace = TRUE) But now the 'start' argument seems to be the problem. Looking at the model coefficients: alpha beta gamma -49.108008320 52.394172340 0.005269907 If I change the alpha and beta values inside start..I still get the error...
Felipe D. Carrillo Supervisory Fishery Biologist Department of the Interior US Fish & Wildlife Service California, USA http://www.fws.gov/redbluff/rbdd_jsmp.aspx >________________________________ >From: Bert Gunter <gunter.ber...@gene.com> >To: Felipe Carrillo <mazatlanmex...@yahoo.com> >Cc: "r-help@r-project.org" <r-help@r-project.org> >Sent: Thursday, July 12, 2012 10:56 AM >Subject: Re: [R] nls question > > >Read the Help file! > >?nls ## Note the "control" argument >?nls.control > >-- Bert > > >On Thu, Jul 12, 2012 at 10:47 AM, Felipe Carrillo <mazatlanmex...@yahoo.com> >wrote: > > Hi: >> Using nls how can I increase the numbers of iterations to go beyond 50. >> I just want to be able to predict for the last two weeks of the year. >> This is what I have: >> >> weight_random <- runif(50,1,24) >> weight <- sort(weight_random);weight >>weightData <- data.frame(weight,week=1:50) >> weightData >>plot(weight ~ week, weightData) >>M_model <- nls(weight ~ alpha + beta*exp(gamma*week), weightData, >> start = c(alpha = 0.0, beta = 1, gamma = 0.2), trace = TRUE) >> >>### I get the error below: >>Error in nls(weight ~ alpha + beta * exp(gamma * week), weightData, start = >>c(alpha = 0, : >> number of iterations exceeded maximum of 50 >> >> >>M_model >>### predict for another 2 weeks >>newD <- data.frame(week = 1:52);newD >>newD$pred_wt <- predict(M_model, newD) >>newD >>plot(pred_wt ~ week, newD, pch = 4, col = "red", ylab = "Weight", xlab = >>"Week") >>with(weightData, points(week, weight,col='blue')) >> >> >>Felipe D. Carrillo >>Supervisory Fishery Biologist >>Department of the Interior >>US Fish & Wildlife Service >>California, USA >>http://www.fws.gov/redbluff/rbdd_jsmp.aspx >> >> [[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. >> >> > > >-- > > > >Bert Gunter >Genentech Nonclinical Biostatistics > >Internal Contact Info: >Phone: 467-7374 >Website: > >http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm > > > > [[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.
