Dear all, I have one Model (M3) fitted using the lme package, and I have checked the correlation structure of within-group errors using plot(ACF (M3,maxLag=10),alpha=0.05) But now I am not sure how to interpret this plot for the empirical autocorrelation function. The problem is that I am used to see/interpret diagrams in which all the autocorrelation Lags, except lag-1, are inside the confidence envelopes, or those plots where only Lags 1 and 2 are outside those envelopes. But how should I interpret my ACF plot, where Lags 1, 7, 8 and 9, are those outside those envelopes? Is there any correlation structure? Which one might that be? AR1()? Also, I have used the plot of the empirical ACF of the normalized residuals, but it gives exactly the same results. Could you please help me? Best regards Sara Mouro Sara Maltez Mouro Centro de Ecologia Funcional Departamento de Botânica Universidade de Coimbra sara@gmesintra.com www.uc.pt/ecology/saramaltezmouro [[alternative HTML version deleted]]
Hello. I have one Model (M3) fitted using the lme package, and I have checked the correlation structure of within-group errors using plot(ACF (M3,maxLag=10),alpha=0.05) But now I am not sure how to interpret this plot for the empirical autocorrelation function. The problem is that I am used to see/interpret diagrams in which all the autocorrelation Lags, except lag-1, are inside the confidence envelopes, or those plots where only Lags 1 and 2 are outside those envelopes. But how should I interpret my ACF plot, where Lags 1, 7, 8 and 9, are those outside those envelopes? Is there any correlation structure? Which one might that be? AR1()? Also, I have used the plot of the empirical ACF of the normalized residuals, but it gives exactly the same results. Could you please help me? Best regards Sara Mouro Sara Maltez Mouro Centro de Ecologia Funcional Departamento de Botânica Universidade de Coimbra sara@gmesintra.com www.uc.pt/ecology/saramaltezmouro Sara Maltez Mouro Centro de Ecologia Funcional Departamento de Botânica Universidade de Coimbra sara@gmesintra.com www.uc.pt/ecology/saramaltezmouro [[alternative HTML version deleted]]