#install.packages("astsa")
require(astsa)
help(package = astsa) 


w1 = rnorm(200, sd=1) # Simulate some random normals
w2 = rnorm(200, sd=1)

f1 = c(1, .5, .5, .2) # MA coefficients
f2 = c(1, -.5, -.5, .2) # MA coefficients

# Simulate two MA(3) series; omit the two NAs at the beginning
ma3.1 = na.omit(filter(w1, f1, side=1))
ma3.2 = na.omit(filter(w2, f2, side=1))

par(mfrow=c(2,1))
acf(ma3.1)
acf(ma3.2)