cyclic-random effects tensor for Noam

cyclic_re_tensor.R

# cyclic-random effects tensor for Noam

library(mgcv)


# code adapted from ?gam.model
dat <- gamSim(1,n=400,scale=2) ## simulate 4 term additive truth
## Now add some random effects to the simulation. Response is
## grouped into one of 20 groups by `fac' and each groups has a
## random effect added....
fac <- as.factor(sample(1:20,400,replace=TRUE))
dat$X <- model.matrix(~fac-1)
b <- rnorm(20)*.5
dat$y <- dat$y + dat$X%*%b


# model in the documentation
rm1 <- gam(y ~ s(fac,bs="re")+s(x0)+s(x1)+s(x2)+s(x3),data=dat,method="ML")


# what about a smooth-re interaction?
rm2 <- gam(y ~ te(x2,fac,bs=c("tp","re"))+s(x0)+s(x1)+s(x3),data=dat,method="ML")

# for a cyclic spline need to switch "tp" for "cc" and read
# ?smooth.construct.cc.smooth.spec for info on end points

# not sure how model checking works on such a model!!