Dear Renaud, Thank you very much! So now lme4 has both laplace and adaptive quadrature? Wow, that's really impressive!
Shige On 8/17/05, Renaud Lancelot <[EMAIL PROTECTED]> wrote: > Shige Song a écrit : > > Dear All, > > > > I have two-level data with individual as level-1, birth cohort and > > community as level-2. All the level-2 covariates are generated from > > the level-1 covariates by cross-classifying by cohort and community. > > > >>From what I read, an ordinary three-level model with individual nesed > > within birth cohort nested within community, or individual nested > > within community nested within birth cohort do not work well, neither > > do model with individual nested within community by cohort. The right > > way to go is to estimate a two-level model with two separate random > > effects: within cohort and within community. The question I want to > > ask is: how to do this using lmer? > > > > I tried the following for a simple unconditioal model: > > > > m1 <- lmer(count ~ offset(log(total)) + (1|comm) + (1|cohort), data, > > poisson) > > > > where "count" is the dependent variable, "total" is the exposure > > variable, "comm" is the community ID, and "cohort" is the birth cohort > > ID. Will this be suffice? I got really smalle randome intercept > > (5.0000e-10 for community and 4.4226e-05 for cohort), which got me a > > bit nervous. > > > > Thanks! > > > > Best, > > Shige > > > > ______________________________________________ > > [email protected] mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide! > > http://www.R-project.org/posting-guide.html > > > > The default method to fit generalized mixed-effect models with lme4 is > "PQL" which is fast but not very accurate for the random effects (they > might be underestimated). Try other methods ("Laplace" or "AGQ") to see > if you get different results. > > Best, > > Renaud > > -- > Dr Renaud Lancelot, vétérinaire > Projet FSP régional épidémiologie vétérinaire > C/0 Ambassade de France - SCAC > BP 834 Antananarivo 101 - Madagascar > > e-mail: [EMAIL PROTECTED] > tel.: +261 32 40 165 53 (cell) > +261 20 22 665 36 ext. 225 (work) > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
