Caution: For a design with nominal factors, the matrix in the Model Matrix script saved by the Save X Matrix option is not the coding matrix used in fitting the linear model. You can obtain the coding matrix used for fitting the model by selecting the option Save Columns > Save Coding Table in the Fit Model report that you obtain when you run the Model script.
Note: You can set a preference to always save the matrix script. Select File > Preferences > Platforms > DOE. Check Save X Matrix.
The model matrix describes the design for the experiment. The model matrix has a row for each run and a column for each term of the model specified in the Model outline. For each run, the corresponding row of the model matrix contains the coded values of the model terms:
The moments matrix is dependent upon the model effects but is independent of the design. It is defined as follows:
where denotes the model effects corresponding to factor combinations of the vector of factors, , and R denotes the design space. For additional details concerning moments and design matrices, see Goos and Jones (2011, pp 88-90) and Myers et al. (2009). Note that the moments matrix is called a matrix of region moments in Myers et al. (2009, p. 376).
From the Custom Design red triangle menu, select Save X Matrix. After the design and the table are created, in the Custom Design table, the Moments Matrix and Model Matrix scripts, and if the design is a split plot, the V Inverse script, are saved as table properties.
Select Edit from the red triangle next to either the Moments Matrix, Model Matrix, or V Inverse script. The script shows the corresponding matrix. You can copy this matrix into scripts that you write.
Tip: To see the log, select View > Log (Window > Log on the Macintosh).
1.
Select DOE > Custom Design.
3.
Click Interactions > 2nd.
5.
Using the Default Number of Runs (12), click Make Design and then Make Table.
Moments Matrix Script
7.
If it is not already open, select View > Log (Window > Log on the Macintosh).
10.
Click Run.
dt = New Table( "Model Matrix" );
dt << Set Matrix( X );
12.
Click Run.

Help created on 9/19/2017