Configuring the Optimal Latin Hypercube DOE Matrix Sampling Method

From the Sampling Options screen or the Error Analysis Sampling Options screen, select Optimal Latin Hypercube from the Technique list.

Enter the Number of Points that you want to study. For each defined factor, the levels are defined by uniformly distributing this number of points between the specified lower and upper values. These levels are randomly combined with other factor levels to define each design point to execute.

Select Use a fixed seed to manually specify the seed in the corresponding text box. If this option is not selected, Isight determines the seed randomly.

Note: A fixed seed can also be set and used for the entire model. If a fixed seed is set for the model and also defined separately in the DOE component, Isight uses the one defined in the DOE component. If a fixed seed is set for the model and this option is not selected, the sequence of random numbers is based on the model’s random seed (and, thus, is still reproducible). For information about setting a fixed seed, see the Setting Model Properties.

Select Execute design points in parallel if you want to execute all the design points defined by the design matrix for execution simultaneously.

You can use this option only if you are using a multiple CPU system or if you are connected to a SIMULIA Execution Engine.

Click Next.

The DOE Factor Attributes screen appears.

If desired, change any of the values for the factor:

Click Update factor baselines to current values when executing if you want the baseline values updated to the current parameter values before executing.

If Isight previously modified a parameter, this option allows for automatic updating of the baseline of all factors to the current parameter values in Isight, prior to executing the DOE technique, which will readjust the values to be studied appropriately. By default, this option is not selected and the user-defined settings are retained. This option is useful if the DOE technique is executed after another element of the simulation process flow that might change the parameter values (e.g., after an Optimization component), so that the DOE study can be performed around the new design point.

Click Next.

The DOE Design Matrix screen appears. This screen displays the design matrix generated for the specified technique and the factors selected and attributes specified.

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.

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.

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

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 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.