Re: [R] nlminb doesn't converge and produce a warning

2011-01-22 Thread Prof. John C Nash
Kamel, You have already had several comments suggesting some ideas for improvement, namely, 1) correct name for iteration limit (Karl Ove Hufthammer) 2) concern about number of parameters and also possibilities of multiple minima (Doug Bates) 3) use of optimx to allow several optimizers to be t

Re: [R] nlminb doesn't converge and produce a warning

2011-01-21 Thread Ravi Varadhan
Ph. (410) 502-2619 email: rvarad...@jhmi.edu -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Karl Ove Hufthammer Sent: Friday, January 21, 2011 6:48 AM To: r-h...@stat.math.ethz.ch Subject: Re: [R] nlminb doesn't converge and pr

Re: [R] nlminb doesn't converge and produce a warning

2011-01-21 Thread Douglas Bates
On Fri, Jan 21, 2011 at 3:51 AM, kamel gaanoun wrote: > Hi Everybody, > > My problem is that nlminb doesn't converge, in minimising a logLikelihood > function, with 31*6 parameters(2 weibull parameters+29 regressors repeated 6 > times). Hmm, the length of the parameter vector shown below is 189,

Re: [R] nlminb doesn't converge and produce a warning

2011-01-21 Thread Karl Ove Hufthammer
kamel gaanoun wrote: > I use nlminb like this : > res1<-nlminb(vect, V, lower=c(rep(0.01, 12), rep(0.01, 3), rep(-Inf, > n-15)), upper=c(rep(Inf, 12), rep(0.99, 3), rep(Inf, n-15)), control = > list(maxit=1000) ) > > and that's the result : > > Message d'avis : > In nlminb(vect, V, lower = c(rep

[R] nlminb doesn't converge and produce a warning

2011-01-21 Thread kamel gaanoun
Hi Everybody, My problem is that nlminb doesn't converge, in minimising a logLikelihood function, with 31*6 parameters(2 weibull parameters+29 regressors repeated 6 times). I use nlminb like this : res1<-nlminb(vect, V, lower=c(rep(0.01, 12), rep(0.01, 3), rep(-Inf, n-15)), upper=c(rep(Inf, 12),