Hi everyone I dont know how to code in SAS but I do know how to code in R. Can someone please be kind enough to translate this into R code for me: proc mixed data = small method = reml; class id day; model weight = day/ solution ddfm = bw; repeated day/ subject=id type = unstructured; run; ================== so far i think it is gls(weight~day,corr=corSymm(???),method="REML",data=small) my main problem is I dont know how to get the unstructured covariance matrix to work Thank you -- View this message in context: http://r.789695.n4.nabble.com/SAS-to-R-tp2286695p2286695.html Sent from the R help mailing list archive at Nabble.com.