Fit Data Options

When a fit is run, but before anything is inserted into the worksheet, the Fit Time Series Results window will be displayed; from this window, a time series can be selected to insert into an @RISK worksheet. The Options panel of the Time Series Fitting and Time Series Batch Fitting windows (Figure 1, right) includes the configurations for the results of the fitting process. These options include the number of elements (i.e. the number of time periods) the model will include, as well as the Fit Statistic used to determine best fit for the time series models that are tested.

The full list of options available in this panel are:

• Series' Starting Point - Configure how the time series will be related to the existing data set.
• • Last Value of Dataset - The results will start just after the last value of the input data set. Use this to forecast future values.
  • First Value of Dataset - The results will start at the same point in time as the input data set (the first data point).
  • i-th Value of Dataset - The results will start just after the i-th value of the input data set. That index is specified in the ‘Start Index’ field.
• Number of Elements - Only available when 'Series Starting Point' is set to 'Last Value of Dataset', or in Batch Fitting mode. The number of data points (representing time periods) that will be included in the resulting time series model tested in the fitting process.
• Fit Statistic - Select the fit statistic - AIC or BIC - that will be used to determine best fit for the time series models included in the fitting process.