Fig. 1From: Portmanteau test statistics for seasonal serial correlation in time series modelsThe empirical 5 % significance level of the seasonal portmanteau test statistics \(Q_{m}(4),\hat{Q}_{m}(4),\tilde{Q}_{m}(4)\), and \(\mathfrak {D}_{m}(4)\) at lag \(m=10\), for a fitted SAR \((1)_{4}\) model to series with lengths \(n=50,100,150,200,250,300,350,400,450\) and 500 simulated from a Gaussian quarter SAR model with a coefficient \(\Phi = 0.3\) Back to article page