[R] monte carlo simulations/lmer

[Eduardo Leoni]

Hi - I am doing some monte carlo simulations comparing bayesian (using
Plummer's jags) and maximum likelihood (using lmer from package lme4
by Bates et al).

I would like to know if there is a way I can flag nonconvergence and
exceptions. Currently the simulations just stop and the output reads
things like:

Error in optim(.Call("lmer_coef", x, 2, PACKAGE = "Matrix"), fn, gr,
method = "L-BFGS-B",  :
    L-BFGS-B needs finite values of 'fn'
In addition: Warning message:
Leading minor of size 1 of downdated X'X is indefinite

Error in .local(object, ...) : Leading 2 minor of Omega[[1]] not
positive definite
In addition: Warning messages:
1: optim or nlminb returned message ERROR: ABNORMAL_TERMINATION_IN_LNSRCH
in: "LMEoptimize<-"(`*tmp*`, value = list(maxIter = 200, msMaxIter = 200, 
2: optim or nlminb returned message ERROR: ABNORMAL_TERMINATION_IN_LNSRCH
in: "LMEoptimize<-"(`*tmp*`, value = list(maxIter = 200, msMaxIter = 200, 


thanks for any help.

-eduardo