Ana You are estimating a random coefficient model on 5 individuals (mean and variance). Are you sure this is wise?
Ross Darnell ----- Original Message ----- From: Ana Conesa <[EMAIL PROTECTED]> Date: Thursday, July 5, 2007 1:21 am Subject: [R] questions on lme function > > Dear list, > > I am using the lme funcion to fit a mixed model for the time response > of a number of physiological variables. The random variable would be > the individual on which physiological variables are measured at > different time points. I have 4 time points, 5 individuals and 3 > replicates per condition (time/individual), and I would like to fit > a quadratic model on time. The model I am using is > > > mm <- lme(myvar ~ time + time2, random= ~ time|individual, > data=clinical) > > being time2 = time*time > > I have a number of questions > > 1) I am not very sure the random effect is correctly modeled. > Would I > need to include the time2 variable aswell? > > 2) I would like to extract the F statistics of the model, and I do > not find a function for this. Is this possible? > > 3) depending of the variable I take, I frequently obtain a > convergence error as a result of the lme funcion. Any ideas on what > to do to improve convergence? > > Thank you > > Ana Conesa, PhD > Centro de Investigacion Principe Felipe > Avda. Autopista Saler 16 46013 Valencia > http://bioinfo.cipf.es > > ______________________________________________ > 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.htmland provide commented, minimal, self-contained, > reproducible code. > ______________________________________________ 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 and provide commented, minimal, self-contained, reproducible code.