###RANDOM WALKS
	N<-321
	index<-seq(0,(N-1)/12,1/12)
	u<-rnorm(N)
	y<-cumsum(u)
	plot(index,y,type="l",xlab="year",ylab="")
	fm<-lm(y~index)
	lines(index,fm$fitted.values,col="blue")
	z<-range(y)
	z0<-max(abs(z))
	temp<-(abs(z)==z0)
	A<-round(summary(fm)$coefficients[2,],3)
	text(0.5, z[temp], paste("slope: ",A[1],"; t stat:", A[3]),pos=4,cex=1,font=2)
#ARMA (0.92, -0.32, sd=0.11)
	N<-321
	ar1<-0.9216
	ma1<- -0.3159
	index<-seq(0,(N-1)/12,1/12)
	u<-rnorm(N+200,sd= 0.1101969)
	y<-arima.sim(n=(N+200),model=list(ar=ar1,ma=ma1), innov=u)
	y<-y[201:(N+200)]
	plot(index,y,type="l",xlab="year",ylab="")
	fm<-lm(y~index)
	lines(index,fm$fitted.values,col="blue")
	z<-range(y)
	z0<-max(abs(z))
	temp<-(abs(z)==z0)
	A<-round(summary(fm)$coefficients[2,],4)
	text(0.5, z[temp], paste("slope: ",A[1],"; t stat:", A[3]),pos=4,cex=1,font=2)