The
SpruceGrpd
data come from a balanced design. There are 23 measurements
on 79 trees, with two dummy time points at 366 and 731 to mark
the border between growing seasons.
Each time series is the size of a young sitka spruce
tree measured as the log(square of the diameter X height).
There are 79 trees over a three-year period. The time is days since
January 1, 1987. The first 54 trees were grown in an atmosphere with
introduced ozone at 70ppb, 27 trees in each of two growing chambers.
The remaining 25 trees
are controls, 12 and 13 trees in each of two chambers.
## Make between seasons independent. data<-recordDesign(cluster="Subject",data=SpruceGrpd,record="Time") blk<-data.frame(layer.id=c(1,1,1), begin.row = c(1, 12,18), begin.col = c(2,13,19), end.row = c(9,15,24), end.col = c(10,16,25)) corDes<-corDesign(size=25,type.layer=list(type="contAR",x.layer="Time"), block=blk,data=data[data$clusterID==1,]) gee(y~Time + group, cluster = cbind(clusterID,recordID), family="gaussian", link="identity", correlation=corDes, variance="glm.scale", data=data)