# beer Daten von
# http://134.76.173.220/beer.zip
beer <- read.csv2( " beer.csv " )
beer <- ts(beer[,1],start=1956,freq=12)
# Regression mit Fourier:
logbeer<-log(beer)
t <- (1:length(beer))/12+1956
t2<-t^2
cos.t<-cos(2*pi*t)
sin.t<-sin(2*pi*t)
pdf("ts6.pdf",width=8,height=3)
par(mar=c(4,4,2,1))
plot(logbeer,ylab="log(Produzierte Biermenge)",xlab="Zeit",col=gray(0.5))
res <- ltsReg(logbeer~t+t2+cos.t+sin.t)
lines(t,res$fit,col=4,lwd=1)
dev.off()