On 14.02.2010 21:20, Benjamin Cheah wrote:
Hi all, I've been struggling with trying to specify a diagnoal matrix for linear mixed effects model. I think I've got nearly everything correct, except the following message appears: In lme.formula(fixed = fwave ~ sex + sexXbulbar + visit + age + : Fewer observations than random effects in all level 1 groups Not sure if i've provided enough details, but I'm basically trying to perform a mixed effects model analysis, controlling for several covariates. Incorporating random effects for the intercept and slope. What does the second line, 'Fewer observations than random effects in all level 1 groups' mean?
That your data is lacking degrees of freedom? In short: You need at least one observation for each parameter estimate to be able to estimate any coefficients, and you need much more in order to get sensible results. Hence you need either more data or need to estimate less parameters.
Best, Uwe Ligges
Many thanks in advance, Ben Cheah __________________________________________________________________________________ [[elided Yahoo spam]] [[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.
______________________________________________ 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.