Dear Yu, What do you mean exactly by "exmpty cell" ?
But you can try, the following packages which might help you: gee and yags. But I am not sure. Best Ozgur -- View this message in context: http://r.789695.n4.nabble.com/empty-cell-when-running-GEE-for-binary-data-tp4635483p4635504.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.