Testing Problem:the prediction results might be incorrect

[JayVae]

@signaflo Hi Sorry to bother you. I run a Main.java according to your Wiki, the program can run.However, after I have checked the results, I found something strange: the prediction results after 2013-04-01 are all too small compared to before, so I want to assure if there is some problem in my Main.java.Below I will paste my Main.java and results so that you can better check.

Here is the Main.java: public class Main2 {

public static void main(String[] args){
    TimeSeries timeSeries = TestData.debitcards;

    ArimaOrder modelOrder = ArimaOrder.order(2, 4, 6, 0, 1, 1);

    Arima model = Arima.model(timeSeries, modelOrder);

    System.out.println(model.aic()); // Get and display the model AIC

    Forecast forecast = model.forecast(12);

    System.out.println(forecast);
}

}

Here is result: `	Date	Forecast	Lower 95.0%	Upper 95.0%
2013-01-01T00:00	144328.7145	144222.6794	144434.7496
2013-02-01T00:00	890130.1238	889636.4510	890623.7965
2013-03-01T00:00	3562769.397	3561322.414	3564216.379
2013-04-01T00:00	1.095551038	1.095211425	1.095890651
2013-05-01T00:00	2.833212465	2.832518799	2.833906131
2013-06-01T00:00	6.473400261	6.472112782	6.474687739
2013-07-01T00:00	1.347106513	1.346883862	1.347329164
2013-08-01T00:00	2.604723814	2.604359301	2.605088327
2013-09-01T00:00	4.745488526	4.744917359	4.746059693
2013-10-01T00:00	8.230283109	8.229419808	8.231146410
2013-11-01T00:00	1.369331700	1.369205099	1.369458301
2013-12-01T00:00	2.198720933	2.198540000	2.198901866

`

[signaflo]

Hi @JayVae.

The order of the Arima model is very strange. I would expect some wacky results with 4 differences. In the example, I use an order of (0, 1, 1, 0, 1, 1), but I see you're using (2, 4, 6, 0, 1, 1).