Andrew Perrin
2002-Jun-02 14:56 UTC
[R] dichotomous independent variables in binomial glmm model
This question is a followup on the one I posted Friday (r-project.org/nocvs/mail/r-help/2002/4485.html). I believe I have narrowed the problem to the observation that models fail to converge when they have dichotomous predictors; to wit: glmmPQL(random = ~1 | groupid/participantid, fixed=r.logic.morality ~ realage, data=fgdata.10statements.df, na.action=na.omit, niter=50, family=binomial) works fine, but glmmPQL(random = ~1 | groupid/participantid, fixed=r.logic.morality ~ is.prot data=fgdata.10statements.df, na.action=na.omit, niter=50, family=binomial) fails with: iteration 1 Error in MEEM(object, conLin, control$niterEM) : Singularity in backsolve at level 0, block 1 This makes sense to me, as a dichotomous variable could be expected to provide insufficient variability in a transformed matrix. Unfortunately, though, I need to use dummy variables as fixed effects. Any advice? Thanks. ---------------------------------------------------------------------- Andrew J Perrin - unc.edu/~aperrin Assistant Professor of Sociology, U of North Carolina, Chapel Hill clists at perrin.socsci.unc.edu * andrew_perrin (at) unc.edu -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._