I am helping a student with some logistic regression analyses and we are getting some strange inconsistencies regarding a warning about factor levels being dropped when running predict.glm(, newdata = ournewdata) on the logistic regression model object. We have checked multiple times that the factor levels have been defined similarly on both data sets (one used to estimate model and the newdata) and that values occur for all factor levels in both data sets. When I run these commands on my version of R (3.2.5) on a Windows 7 OS I do not get the warnings. When the student runs them on her version of R (not sure what number hers is) on her Mac, she gets these warnings constantly. I've checked some records manually by doing the algebra and the predict.glm() function is working correctly incorporating the factor levels on my machine. Any thoughts???
Brian Brian S. Cade, PhD U. S. Geological Survey Fort Collins Science Center 2150 Centre Ave., Bldg. C Fort Collins, CO 80526-8818 email: ca...@usgs.gov <brian_c...@usgs.gov> tel: 970 226-9326 [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.