1. postscript(file="sales.eps",paper="letter")
x<-BJsales.lead;y<-BJsales
par(mfrow=c(2,1))
plot(y,type="l",main="Sales",las=1)
plot(x,type="l",main="Leading series",las=1)
plot(diff(y),type="l",main="Difference sales",las=1)
plot(diff(x),type="l",main="Difference leading series",las=1)
graphics.off()

4. postscript(file="sales1.eps",hor=F,paper="letter")
acf(cbind(x,y),main="sales and leader")
acf(cbind(diff(x),diff(y)),main="diff(sales) and diff(lead)")
par(mfrow=c(3,1))
junk<-spec.pgram(cbind(diff(x),diff(y)),spans=5,taper=0,demean=T,detrend=F,xlab="",ylab="",main="Smoothed spec of diffs - red is sales")
plot(junk$freq,junk$coh,type="l",las=1,main="Squared coherency",ylim=c(0,1),xlab="")
plot(junk$freq,junk$phase,type="l",las=1,main="Phases",ylim=c(-pi,pi),xlab="")
graphics.off()