John Your model is not properly specified for lme. You have not included any random effects or a grouping variable. Let me assume just for sake of argument that you want to include a random effect for the intercept and for time. Your lme specification would be
> fm1 <- lme(Velocity~time, random=~time|ID, gate) Where ID is a grouping variable. I would encourage you to work with lmer, which is now found in the Matrix package. The call to lmer differs slightly from lme, > fm1 <- lmer(Velocity~time + (time|ID), gate) I hope this is helpful, Harold -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of John Sorkin Sent: Thursday, July 14, 2005 1:05 PM To: [email protected] Subject: [R] Error running lme. I am trying to fit lme using R 2.1.1 under Windows 2k. I am getting the following message noted below. Any suggestions that would help me correct my error would be greatly appreciated. Thanks, John > fit1lme<-lme(Velocity~time,data=gate) Error in getGroups.data.frame(dataMix, groups) : Invalid formula for groups John Sorkin M.D., Ph.D. Chief, Biostatistics and Informatics Baltimore VA Medical Center GRECC and University of Maryland School of Medicine Claude Pepper OAIC University of Maryland School of Medicine Division of Gerontology Baltimore VA Medical Center 10 North Greene Street GRECC (BT/18/GR) Baltimore, MD 21201-1524 410-605-7119 -- NOTE NEW EMAIL ADDRESS: [EMAIL PROTECTED] [[alternative HTML version deleted]] ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
