Initializing Approximations and Viewing the Data

You can initialize your approximation immediately after creating it, or you can initialize it after it has been created from the Design Gateway or the Runtime Gateway. Approximations can also be initialized automatically at run time when you submit a model for execution.

If an approximation that uses resizable arrays was initialized at design time and the array dimensions changed at run time prior to executing the approximation, the approximation will render itself not initialized and will re-initialize.

A component that has an approximation cannot change array dimensions during approximation initialization. The initialization will either fail or produce invalid results.

Important: If you are selecting a component that is in a Task Plan, you must select the component using the model explorer.

This task shows you how to:

Initialize a New Approximation

If you have just finished creating a new approximation, you can initialize it.

  1. Click Finish to create the new approximation.
    The Initialize Approximation screen appears.
  2. Click Yes.
    The contents of the Data Points tab are added as soon as the data points are executed by Isight. The contents of the Coefficients Data tab are displayed only after the initialization is complete.
  3. After initialization is complete, you can also do the following:
    • Select the Coefficients Data tab to view the resulting coefficients calculated from generating the approximation.
    • Select Export to save your data points, error points, coefficient data, or approximation error analysis summary to a text file for viewing in another program. You can save only one set of points at a time.

      If you save the coefficient data, you can use it when creating another approximation (see Creating Approximations Using a Coefficient File). If you are working with the RBF or RSM techniques, you can select Export to Excel (see Exporting Approximation Data to Excel). You can also select Export approximation error analysis summary to get a full summary of the approximation (see Exporting Approximation Error Analysis Summary). You can also save the information as a separate Approximation component. In this case, you save the component as a model (*.zmf) file and the coefficient data as a text file, which is used as the data file for the Approximation component (see Approximation Component in the Isight Component Guide).

    • Select Clear Data to delete the current initialization data.

      Note: If you use this option and then do not immediately re-initialize the approximation, the Initialize button replaces the View Data button when the Approximations dialog box is accessed.

Initialize an Existing Approximation from the Design Gateway

  1. If you are working with an existing approximation from the Design Gateway, do one of the following:
    • Select the component whose approximation you want to initialize on the Sim-flow tab or in the model explorer, and click the Approximations button on the component title bar.
    • Right-click the component on the Sim-flow tab or in the model explorer, and select Approximations.
    The Approximations dialog box appears.
  2. In the Activated column, select the approximation that you want to initialize.
  3. Click Initialize.
    The Approximation Initialization screen appears.
  4. Click Initialize Now.
  5. If desired, select Re-initialize to initialize the approximation again.

    The Re-Initialize Approximation dialog box appears.

    1. Determine if you want to preserve or delete existing data:

      Option Description
      Preserve existing sampling data and generate additional random points using the same input sampling ranges Enter the number of additional random points in the text box. Isight adds the points using sequential sampling if the approximation technique supports it; otherwise, Isight adds the points randomly.
      Delete existing sampling points and generate new random points after reducing the input sampling ranges Enter the percentage by which you want to reduce the input sampling.
      Invoke Approximation Wizard to edit the configuration of the approximation Reopens the Approximation Wizard, allowing you to update the approximation settings and then re-initialize.

    2. Click OK.
  6. While the approximation is initializing, you can do any of the following:
    • Select the Data Points tab to view the values for input and output parameters for each sample point.
    • Select the Error Analysis Points tab to view the values for input and output parameters for each error analysis point. For more information, see Analyzing Approximation Errors.
    • Select the Log Messages tab to view all log messages associated with the initialization. You can filter the log messages using the Log Filter list. For more information on the different log levels, see Setting Preferences.
  7. After initialization is complete, you can also do the following:
    • Select the Coefficients Data tab to view the resulting coefficients calculated from generating the approximation.
    • Select Export to save your data points, error points, coefficient data, or approximation error analysis summary to a text file for viewing in another program. You can save only one set of points at a time.

      If you save the coefficient data, you can use it when creating another approximation (see Creating Approximations Using a Coefficient File). If you are working with the RBF or RSM techniques, you can select Export to Excel (see Exporting Approximation Data to Excel). You can also select Export approximation error analysis summary to get a full summary of the approximation (see Exporting Approximation Error Analysis Summary). In addition, you can save the information as a separate Approximation component: you save the component as a model (*.zmf) file and the coefficient data as a text file, which is used as the data file for the Approximation component (see Approximation Component in the Isight Component Guide).

    • Select Clear Data to delete the current initialization data.

      Note: If you use this option and then do not immediately re-initialize the approximation, the Initialize button replaces the View Data button when the Approximations dialog box is accessed.

    • Select Error Analysis to view the quality of the approximation for each response (see Analyzing Approximation Errors).
    • Select Visualize to manually interact with the initialized approximation and observe, graphically, how changing the input values affects the output values and the shape of the output function (see Visualizing Approximations).
  8. Click Close to exit the Approximation Initialization dialog box and to return to the Approximation dialog box.
  9. Click Close to exit the Approximation dialog box and to return to the Design Gateway.

Initialize an Existing Approximation from the Runtime Gateway

  1. If you are working with an existing approximation from the Runtime Gateway, do the following:
    1. Select the component whose approximation you want to initialize on the Sim-flow tab or in the model explorer.
    2. Click the Visual Design tab and select the approximation from the list next to the component name.
    3. Click Initialize Now.
  2. While the approximation is initializing, you can do any of the following:
    • Select the Data Points tab to view the values for input and output parameters for each sample point.
    • Select the Error Analysis Points tab to view the values for input and output parameters for each error analysis point. For more information, see Analyzing Approximation Errors.
    • Select the Log Messages tab to view all log messages associated with the initialization. You can filter the log messages using the Log Filter list. For more information on the different log levels, see Setting Preferences.
  3. After initialization is complete, you can also do the following:
    • Select the Coefficients Data tab to view the resulting coefficients calculated from generating the approximation.
    • Select Export to save your data points, error points, coefficient data, or approximation error analysis summary to a text file for viewing in another program. You can save only one set of points at a time.

      If you save the coefficient data, you can use it when creating another approximation (see Creating Approximations Using a Coefficient File). If you are working with the RBF or RSM techniques, you can select Export to Excel (see Exporting Approximation Data to Excel). You can also select Export approximation error analysis summary to get a full summary of the approximation (see Exporting Approximation Error Analysis Summary). You can also save the information as a separate Approximation component. In this case you save the component as a model (*.zmf) file and the coefficient data as a text file, which is used as the data file for the Approximation component (see Approximation Component in the Isight Component Guide).

    • Select Clear Data to delete the current initialization data.

      Note: If you use this option and then do not immediately re-initialize the approximation, the Initialize button replaces the View Data button when the Approximations dialog box is accessed.

  4. Continue working with other approximations or switch to another tab.