Hi i run arima.sim(n=100,n.start=9,list(ar=c(0.4)),sd=sqrt(3)), but i need that the firs value be 9, i mean x_(-1). Thanks -- View this message in context: http://r.789695.n4.nabble.com/Simulate-AR-1-starting-from-X-number-tp4276550p4276550.html Sent from the R help mailing list archive at Nabble.com.