Setting Criteria and Searching the Design

You can search your design for certain criteria. You can determine which parameters, parameter values, objectives, or constraints to use in the search.

Note: The Design Search automatically uses information (constraints and objectives) set on the Design Gateway Formulation tab for the corresponding component. These settings can be altered, as desired, but will not change the settings on the Formulation tab. For more information on problem formulations, see Using Problem Formulations.

In addition, any changes are propagated to the Parameters tab and reflected on the History tab (with the run grading information being updated for the new bounds). For more information on run grading, see Understanding Run Grading.

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

  1. Select the component whose approximation you want to visualize.

    • From the Design Gateway,

      • Select a component 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.

      1. In the Activated column, select the approximation that you want to visualize.
      2. Click Visualize.
      3. Click the Design Search tab.

        The search options appear.

        Tip: You can also access this interface from the Approximation Wizard after initialization by clicking Visualize. For more information, see Initializing Approximations and Viewing the Data.

    • From the Runtime Gateway,

      1. Select a component 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 title bar.
      3. Click the Design Search subtab.

  2. From the Design Variables tab, select the desired design variables:

    By default, all the design variables are selected. You can click the check box adjacent to a design variable to remove it from the search. The initial settings are based on the range displayed on the Graphs tab or the Visualization tab (see Exploring the Design Space Manually). Any changes made using the Design Variables tab are transferred to the Graphs tab and the Visualization tab.

  3. From the Constraints tab, enter the following values, as desired:

    Option Description
    Lower Bound Specify the Lower Bound for the constraints in the corresponding column. The Lower Bound appears as a blue line in the graphs at the bottom of the Design Search tab.
    Upper Bound Specify the Upper Bound for the constraints in the corresponding column. The Upper Bound appears as a red line in the graphs at the bottom of the Design Search tab.
    Target Specify the Target for the constraints in the corresponding column. The Target appears as a green line in the graphs at the bottom of the Design Search tab.

  4. From the Objectives tab, enter the following values, as desired:

    • Click the Direction column to specify whether or not you want to minimize the objective, maximize the objective, or set a target for the objective.

    • If you selected target in the Direction column, set the objective’s target in the corresponding column.

    • Set the objective’s Scale Factor in the corresponding column. Isight uses the Scale Factor to equalize the magnitude of objectives when several parameters of vastly different magnitudes are selected.

    • Set the objective’s Weight Factor in the corresponding column. Isight uses the Weight Factor to add importance to one of the selected objectives.

  5. In the Runtime Gateway, you can set the search options. The search options allow you to set the optimization technique (and options) and to update the design space graphs during optimization.

    Note: When approximations are created on Optimization components, the optimization technique and options defined within the Optimization component are used for the design search.

    1. Click Options on the upper right side of the Design Search tab.

      The Design Search Options dialog box appears.

    2. Select the Technique tab, and select the optimization technique to use for the design search from the Technique list
    3. Set the technique’s tuning parameters. For more information on selecting optimization techniques and setting their tuning parameters, see the Isight Component Guide.
    4. Click the General tab and, if desired, select Update design space graphs during optimization. If this option is selected, all graphs on the Graphs tab are updated at each new point during the design search (optimization). Using this option slows the process down, but it can be useful in tracking the path of the search through the design space as opposed to just viewing the history of values (i.e., the graphs shown on the Design Search tab).
    5. Click OK to close the Design Search Options dialog box.

  6. Click Search.

    Isight executes the search and the Inputs History and Outputs History graphs are updated to show the results.