[R-sig-ME] confidence intervals for random slopes

[Bokony Veronika]

Dear all,

let me ask your advice about calculating confidence intervals for random slopes. I have a random intercept & random slope model like this:

lme(Y ~ X * fixfactor, random=~X|randomfactor)

where randomfactor has 9 levels. For each of these 9 levels, I can calculate the slope of X from the fixed and random effect estimates. I would like to add some measure of uncertainty to each of these 9 estimates, i.e. an SE or CI for each random slope. The random effects SD which is given by the lme summary output is not what I'm interested in. I got a very general tip that I could calculate credible intervals from posterior distributions using a bayesian approach, but I found no evident way of extracting these from MCMCglmm either.

I would be very grateful for any working example that can achieve this.

Best regards,

Veronika


Veronika Bókony PhD
"Lendület" Evolutionary Ecology Research Group
Plant Protection Institute, Centre for Agricultural Research 
Hungarian Academy of Sciences
Herman Ottó út 15.
H-1022 Budapest, Hungary
+36 1 3918609
http://www.nki.hu/lendulet-evolucios-okologiai-kutatocsoport
http://ornithology.limnologia.hu/people/veronika-bokony/