Thanks to some help by Doug Bates (and the updated version of the Matrix package), I've refined my question about fitting nested and non-nested factors in lmer(). I can get it to work in linear regression but it crashes in logistic regression. Here's my example:
# set up the predictors n.age <- 4 n.edu <- 4 n.rep <- 100 n.state <- 50 n <- n.age*n.edu*n.rep age.id <- rep (1:n.age, each=n.edu*n.rep) edu.id <- rep (1:n.edu, n.age, each=n.rep) age.edu.id <- n.edu*(age.id - 1) + edu.id state.id <- sample (1:n.state, n, replace=TRUE) # simulate the varying parameters a.age <- rnorm (n.age, 1, 2) a.edu <- rnorm (n.edu, 3, 4) a.age.edu <- rnorm (n.age*n.edu, 0, 5) a.state <- rnorm (n.state, 0, 6) # simulate the data and print to check that i did it right y.hat <- a.age[age.id] + a.edu[edu.id] + a.age.edu[age.edu.id] + a.state[state.id] y <- rnorm (n, y.hat, 1) print (cbind (age.id, edu.id, age.edu.id, state.id, y.hat, y)) # this model (and simpler versions) work fine: fit.1 <- lmer (y ~ 1 + (1 | age.id) + (1 | edu.id) + (1 | age.edu.id) + (1 | state.id)) # now go to logistic regression ypos <- ifelse (y > mean(y), 1, 0) # these work fine: fit.2 <- lmer (ypos ~ 1 + (1 | age.id) + (1 | edu.id) + (1 | age.edu.id), family=binomial(link="logit")) fit.3 <- lmer (ypos ~ 1 + (1 | age.id) + (1 | edu.id) + (1 | state.id), family=binomial(link="logit")) # this one causes R to crash!!!!!!! fit.4 <- lmer (ypos ~ 1 + (1 | age.id) + (1 | edu.id) + (1 | age.edu.id) + (1 | state.id), family=binomial(link="logit")) -- All help appreciated. This is for our book on regression and multilevel models, and it would be great if people could get started fitting these models in R before having to do the more elaborate modeling in Bugs. Andrew -- Andrew Gelman Professor, Department of Statistics Professor, Department of Political Science [EMAIL PROTECTED] www.stat.columbia.edu/~gelman Tues, Wed, Thurs: Social Work Bldg (Amsterdam Ave at 122 St), Room 1016 212-851-2142 Mon, Fri: International Affairs Bldg (Amsterdam Ave at 118 St), Room 711 212-854-7075 Mailing address: 1255 Amsterdam Ave, Room 1016 Columbia University New York, NY 10027-5904 212-851-2142 (fax) 212-851-2164 ______________________________________________ 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
