Configuring the Design Matrix

The Design Matrix tab displays the design matrix generated for the technique selected on the General tab and the factors selected and attributes specified on the Factors tab.

If an array was selected as a factor, only a single item is displayed in the design matrix for the entire array. At run time, the individual elements of the array are assigned to columns of the design matrix, as necessary.

  1. Double-click the DOE component icon .

    The DOE Component Editor appears.

  2. From the DOE Component Editor, click the Design Matrix tab.

  3. Depending on the technique that you are using, do the following:

    • Optimal Latin Hypercube technique
      1. Click Generate to create your design matrix.

        Note: If you do not manually generate the design matrix in the component editor, the DOE component automatically generates the matrix as part of the execution. This process may take a significant amount of time. You can view the information displayed on the Status dialog box to see how the matrix generation is proceeding, when it completes, and any errors.

      2. Click Close once the matrix has been created. If you click Close before the design matrix optimization completes, the resulting design matrix is the last one generated during the optimization process.
    • Orthogonal Array and Full-Factorial techniques
      1. Click Options to display any options available for generating the design matrix.
      2. Use the or to change the order in which factors are assigned to columns.

        When using Orthogonal Arrays, the factors are assigned automatically to columns in a way that minimizes confounding with interaction effects. Preference is given to factors in the order they were defined.

      3. Click in the Column cell to assign a factor to that specific column.

        You can define specific columns for factors to be assigned to, and Isight will attempt to assign the factors to those columns exactly (although it may fail if a specified column is not appropriate for a given factor).

    • Fractional Factorial technique
      1. Click Options to display any options available for generating the design matrix.
      2. Use the or to change the order in which factors are assigned to columns.

        When using three-level Fractional Factorials, the factors are assigned automatically to columns in a way that minimizes confounding with interaction effects. Preference is given to factors in the order they were defined.

      3. Click in the Column cell to assign a factor to that specific column.

        You can define specific columns for factors to be assigned to, and Isight will attempt to assign the factors to those columns exactly (although it may fail if a specified column is not appropriate for a given factor).

      4. Edit the Generator, as desired.

        A generator is specified as a sequence of column numbers, separated by a hyphen “-”. For example, “5-6-9” means that the column is generated using columns 5, 6, and 9. Only certain columns have generators, depending upon the fraction selected. For example, 1/2 fractions have a generator only in the last column; 1/4 fractions have generators for the last two columns, and so on.

      5. Determine if you want to set the Fraction or the Number of Runs in the design.
        • Fraction. Select a fraction from the list. By default, the Fraction corresponding to the least number of runs for the selected number of factors and number of levels for each factor is chosen.
        • Number of Runs. Select the number of runs from the list.

          For information about the fractions and number of runs available, see Fractional Factorial Design Technique.

  4. Click in the Show list to select how you want the design matrix displayed.

    Option Description
    Values The actual values to be set at execution.
    Levels The level number as generated by the technique algorithm.

  5. Perform any of the following actions to manipulate the design matrix:

    Option Description
    Deactivate a single design point To deactivate a design point so that it is not executed (the icon appears), click any row number. You can also click the button at the top of the design matrix, or right-click the design matrix and select Skip selected design point(s).
    Deactivate all design points To deactivate all design points in the design matrix, highlight all the design points and click the button. You can also right-click the design matrix and select Skip all design points.

    Note: Deactivating design points is useful when it is known that a specific set of values in the design matrix represents a design that cannot be evaluated for whatever reason.
    Activate a design point To activate a design point that has been set to be skipped, click the icon that represents the design point. The row number reappears. You can also click the button at the top of the design matrix, or right-click the design point and select Activate selected design point(s).
    Activate all design points To activate all the design points in the design matrix, highlight all the design points and click the button. You can also right-click the design matrix and select Activate all design points.
    Add user-defined points to the matrix To add any design point to the design matrix, enter a value for each factor into the empty last row in the table. Typically, the selected DOE technique generates a matrix based on the options and factors selected, but you can add any design points to the matrix. The DOE component will fail to execute if any user-defined point does not have a value for all factors (the cells with missing values for user-defined points are highlighted in pink).
    Paste user-defined points from the clipboard To add a set of points that are already defined in a file, you can copy and paste them directly into the design matrix as new user-defined points by right-clicking and selecting Paste new user-defined points. Pasting new user-defined points will always append the points to the matrix (regardless of whatever cell was selected). If factor names are found in the first row of the copied data, Isight uses those names to identify the appropriate columns of data; otherwise, values are pasted in the same order as they exist in the pasted content. You must confirm that the values pasted are appropriate for the factors in those columns.
    Remove user-defined points from the matrix To remove any user-defined points from the matrix, clear the values from all cells in that row or right-click and select Remove selected user-defined point(s) or Remove all user-defined points.
    Copy the design matrix To copy the design matrix to the clipboard so that it can be pasted elsewhere (e.g., in a text file), click the Copy button above the design matrix or right-click the design matrix and select Copy design matrix.
    Save the design matrix To save the design matrix to a file, click the Save button above the design matrix or right-click the design matrix and select Save.

  6. If desired, you can apply a filter to the design matrix.

    1. Click the button.

      The Design Matrix Filter dialog box opens.

    2. Enter any expression that evaluates to a Boolean or to a number. All input variables and factors can be used within this expression. You can click the button to enter complex expressions and the button to ensure that the expression does not have any errors.

      Isight will not evaluate any design point if the expression evaluates to true or to a numerical value strictly greater than zero.

    Once you provide an expression, the points in the design matrix that are to be filtered appear in red.

    Note: When you use a technique that uses a random seed, the number of runs can be different from that seen in this interface if the random seed is not set. The number of runs can be different when the factor baselines change during execution.

  7. Click OK to save your changes and to close the DOE Component Editor.