Model Browser User's Guide

Setting Up a Space Filling Design

You can toggle coded units for all space-filling designs by selecting the check box at the top.

The default Design drop-down menu item is Latin Hypercube Sampling.

For both Latin Hypercube Sampling and Stratified Latin Hypercube, you can choose from several selection criteria available in a drop-down menu:

• Maximize minimum distance (between points). This is the default.
• Minimize maximum distance (between points)
• Minimize discrepancy -- Minimizes the deviation from the average point density
• Minimize RMS variation from CDF -- Minimizes the Root Mean Square (RMS) variation of the Cumulative Distribution Function (CDF) from the ideal CDF
• Minimize maximum variation from CDF -- Minimizes the maximum variation of the CDF from the ideal CDF

The final two (CDF variation) options scale best with the number of points and it is advisable to choose one of these options for large designs.

The same criteria are available for the Stratified Latin Hypercube.

• You can set the number of points using the controls or by typing in the edit box.
• You can set the ranges for each factor.
• If you select the Enforce Symmetrical Points check box, you create a design in which every design point has a mirror design point on the opposite side of the center of the design volume and an equal distance away. Restricting the design in this way tends to produce better Latin Hypercubes.
• You can use the tabs under the display to view 2-D, 3-D, and 4-D previews.
• Click OK to calculate the Latin Hypercube and return to the main Design Editor.

For a Lattice space-filling design:

• You can choose the lattice size by using the buttons or typing in the edit box.
• You can choose the prime number generator by using the up/down buttons on the Prime number for X edit box.
• You can choose the range for each factor.
• Click OK to calculate the lattice and return to the Design Editor.

Creating a Space Filling Design

Creating an Optimal Design