If these are the only variables, you are missing Type. Swim and Type are both conditioning variables that you need to provide. Maybe your intention is to use Sex instead of Type. Try:
?xyplot And look under x as the 1st argument for xyplot. Rene -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Monday, December 18, 2006 7:19 PM To: [email protected] Subject: [R] Random Effects Model Hello, I am new to R, and I am trying to figure out how to use it for a random effects model. I am using version 2.4.0, and I also have the book Applied Linear Regression by Sanford Weisberg. I have four variables: Swimmer, Sex, Swim, and Difference. Swimmer identifies the number assigned to a particular person. Sex is male/female. Swim identifies the number swim from 1 to 6. Difference is my variable of interest (random). The book says I should run something like this: > library(nlme) > data(FREE) #FREE is my dataset > xyplot(Difference~Swim|Type, group=Swimmer, data=FREE, + panel.groups=function(x,y,...){ + panel.linejoin(x,y,horizontal=FALSE,...)} + ) > m1 <- lme(Difference~Swim+Type, data=FREE, random=~1+Type|Swimmer) > m2 <- update(m1, random=~1|Swimmer) I've pretty much decided that xyplot doesn't work. Instead, I think plot will work much better. I keep getting errors about Type. Can someone explain this to me? Does the code above look right? Any kind of help will be appreciated... Thanks in advance! Ryan ______________________________________________ [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 and provide commented, minimal, self-contained, reproducible code. ______________________________________________ [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 and provide commented, minimal, self-contained, reproducible code.
