set.seed(123)
ma1<-arima.sim(model=list(ma=c(0.7)), n=200)
ma1

set.seed(123)
x1<-w<-rnorm(200)
w
for(t in 2:200) x1[t]=0.7*w[t-1]+w[t]
x1.ts<-ts(x1)
x1.ts

par(mfrow=c(3,2))

plot(ma1, type="l", main="MA(1)")
plot(x1.ts[2:200], type="l", main="MA(1)")

acf(ma1, main="Yt = 0.7*wt-1+wt")
acf(x1.ts[2:200], main="Yt = 0.7*wt-1+wt")

pacf(ma1, main="Yt = 0.7*wt-1+wt")
pacf(x1.ts[2:200], main="Yt = 0.7*wt-1+wt")