I have a time series consisting of 490 days and for each day I have the residual of a forecasting model. I wanted to check if the residuals somehow correlate and calculated the ACF at lag 1 which is
Here is the ACF plot:
Now I wanted to check the linear relationship between lag=0 (denoted as
x1 in the scatterplot) and lag=1 (
x2 in the scatterplot) so I plotted a scatterplot, but I don't see any linear relationship. Why do I have a correlation of 0.42 at lag 1 but I don't see the linearity between lag 0 and 1?
Am I missing a point here?
Update: I uploaded a CSV file with the time series here