Fig. 2From: Portmanteau test statistics for seasonal serial correlation in time series modelsEmpirical power as a function of sample size n and maximum lag \(m= n/5\) comparing seasonal (\(s=4\)) to nonseasonal (\(s=1\)) tests, where series from nonseasonal ARMA (1,1) with \(\phi _{1}=0.9\) and \(\theta _{1}=0.8\) are generated, and a SMA \((1)_{4}\) model is fittedBack to article page