Problem Calculation

NOTE. The option is available only for criterion problem.

Specify criterion problem type in the Problem Type drop-down list:

• Optimal Control Problem. The problem consists in finding such values of controlling variables, at which condition of criterion function optimization is satisfied.

• Forecasting Problem. Models included into the problem are calculated consequently in each scenario point: firstly, all models are calculated by the first scenario point, then all models are calculated by the second scenario point, and so on.

By default, sample periods and forecasting periods match the periods selected on the Periods panel. To correct period data, use the groups of parameters: Sample Period and Forecasting Period.

Operations with period:

• Change period limits. Click the Edit button. Dates can be changed in the Start Date and End Date boxes. Specify the required time period limits.

• Reset period limits. Click the Reset button. Period limits are restored to original state. Period limits can be reset if they were changed.

Changing of data loading period enables the user to load only required data, therefore, optimize problem calculation. By default, data loading period is not set, and start and end loading dates are determined automatically after running calculation problem.

To set data loading period, use the Load Data for a Period group of parameters. Data loading period is set similarly to sample and forecasting periods.

Set the following options in the Calculation Options group:

• Save Calculation History. If the checkbox is selected, problem calculation history is saved. The checkbox is deselected by default, and calculation history is not saved.

NOTE. Calculation history saves only the models that are based on modeling variables.

• Use Saved Models Coefficients. If the checkbox is selected, coefficient values are used, which were saved before, this optimizes calculation. Saving coefficients is only possible for linear regression models. The checkbox is deselected by default, and coefficients are calculated before problem calculation.

• Substitute Empty Values with Zeros. If the checkbox is selected, empty values in variables are replaced with zeroes. The checkbox is deselected by default, and variables remain with empty values.

• Upload Calculated Zeros to Database. The checkbox is selected by default, and zero values obtained on problem calculation are uploaded to the database. If the checkbox is deselected, only non-zero values are saved to the database after problem calculation.

To select a calculation scenario, use the Scenarios tab. The tab displays scenarios added to the modeling problem, which the user has read and write permissions for.

Each scenario has a corresponding checkbox. If the checkbox corresponding to the scenario is selected, the scenario is available for problem calculation. Calculation is executed by all selected scenarios one by one. By default, all scenarios except for the Fact system scenario are selected.

NOTE. Forecasting problems are calculated pointwise rather than sequentially: first, all models are calculated by the first point of the first scenario, then all models are calculated by the first point of the second scenario, and so on.

Click the Run button to run problem calculation.

• In case of uninterrupted calculation, the button name changes to Pause, clicking which pauses problem calculation. To continue calculation, click the Continue button, to interrupt - Stop.
  If any errors or warnings occurred during problem calculation, they will be displayed on the Errors tab.

• In case of step-by-step calculation the Problem Calculation dialog box closes and the Debugging Panel opens:

The Status line displays the current calculation status. To execute the step-by-step calculation, use the following buttons:

• - executes calculation of one problem step.

• - starts problem calculation without stopping at each step.

• - pauses problem calculation.

• - stops problem calculation.

If errors or warnings occurred during the problem calculation, they are displayed in the Status line.

The tab displays the calculation chain, including a number of models. Double-click the required model to edit it.

The tab shows a list of variables, specifying their type (input or output) and identifier. Double-click the variable to view its data.

The tab displays errors that occurred on problem calculation.

The tab displays a table containing data on iterations: the number of iteration and the value of the criterion function on this iteration. A linear chart is plotted using the table data.

NOTE. The tab is available only for optimal control problem on uninterrupted calculation type.