Dear r-helpers, does anyone knows how to constrain the value of parameters in a non-linear mixed model: I've got something like that: nlme(log(response)~z+y*log(var1)+x*log(var2)+log((b*var3+a)/(b*var4+a)^x) where 0<x<1, a<1 and (b*(var3 or var4: range of values similar)+a) between 0 and 1. or even better if you know how to linearize it !!
and another one : What means ? Error in chol((value + t(value))/2) : the leading minor of order 1 is not positive definite (my statical books do not go far enough in the detail. It must be about the Cholesky something if I remember well what I read long-time ago). I'm sorry to bother you with this kind of things, but I'm in a remote place (~18�45'S,26�45'E) (even if e-mails are working at the incredible speed of 4.8 kbits/sec...) without a lot of statistical or computer ressources. Thanks, simon --------------------------------------------------------- Simon Chamaill� Hwange Project CIRAD-CNRS Hwange Main Camp Research P. Bag 5776, Dete (+00 263) 18-647 [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
