Optimization Setup for the Pattern Search (Search-based) Optimizer

Follow this procedure to set up an optimization analysis using the Pattern Search(Search-based) Optimizer. Once you create a setup, you can Copy and Paste it, then make changes to the copy, rather than redoing the whole process for minor changes.

  1. Set up the variables you want to optimize in the Design Properties dialog box.
  2. Select Twin Builder > Optimetrics Analysis > Add Screening & Optimization . The Setup Optimization dialog box appears.
  1. Under the Goals tab, select the optimizer by selecting Pattern Search(Search-based) from the Optimizer drop-down list. The Acceptable Cost and Noise fields are enabled.
  2. Type the maximum number of iterations you want Optimetrics to perform during the optimization analysis in the Max. No. of Iterations text box.
  3. Under Cost Function, click Setup Calculations to open the Add/Edit Calculation dialog box, and add a cost function.
  4. Type the value of the cost function at which the optimization process should stop in the Acceptable Cost text box.
  5. Type the cost function noise in the Noise text box.
  6. If you want to select a Cost Function Norm Type:
    • Select the Show Advanced Option check box. The Cost Function Norm Type drop-down list appears.
    • Select L1, L2, or Maximum.

    A norm is a function that assigns a positive value to the cost function.

    For L1 norm the actual cost function uses the sum of absolute weighted values of the individual goal errors. For L2 norm (the default) the actual cost function uses the weighted sum of squared values of the individual goal error. For the Maximum norm the cost function uses the maximum among all the weighted goal errors. (For further details, see Explanation of the L1, L2, and Max Norms in Optimization.)

    The norm type does not affect Goal settings that use either the Minimize or Maximize condition.

  7. Optionally, click HPC and Analysis Options to select or create an analysis configuration.
  8. In the Variables tab, specify the Min/Max values for variables included in the optimization, and the Min/Max Step Size for the analysis.
    • You may also override the variable starting values by selecting the Override check box and entering the desired value in the Starting Value field.
    • Optionally, modify the values of fixed variables that are not being optimized.
    • Optionally, set Linear constraints.
    • Select the View all columns check box to see all columns, including hidden columns.
  9. In the General tab, specify whether Optimetrics should use the results of a previous Parametric analysis or perform one as part of the optimization process.

    Select the Update design parameters’ value after optimization check box to cause Optimetrics to modify the variable values in the nominal design to match the final values from the optimization analysis.

  10. Use the Options tab if you want to enable use of a fast calculation-update algorithm to speed up Optimetrics and report updates during Optimetrics analyses, and to save the solution data for solved design variations in the analysis.