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Details of the OPTEX Procedure 
See OPTEX4 in the SAS/QC Sample Library 
This example is a continuation of Example 24.2.
You can customize the runs used to initialize the search in the OPTEX procedure. For example, you can use the INITDESIGN=SEQUENTIAL option to use an initial design chosen by the sequential search. Or you can place specific points in a data set and use the INITDESIGN=SASdataset option. In both cases, the search time can be significantly reduced, since the search only has to be done once. This example illustrates both of these options.
The previous example compared the results of the DETMAX and sequential search algorithms. You can use the design chosen by the sequential search as the starting point for the DETMAX algorithm. The following statements specify the DETMAX search method, replacing the default initialization method with the sequential search:
proc optex data=a seed=33805; model afegrsa@2 af*af egr*egr sa*sa; generate n=50 method=detmax initdesign=sequential; run;
The results, which are displayed in Output 24.3.1, show an improvement over the sequential design itself (Output 24.2.2) but not over the DETMAX algorithm with the default initialization method (Output 24.2.1). Evidently the sequential design represents a local optimum that is not the global optimum, which is a common phenomenon in combinatorial optimization problems such as this one.
Output 24.3.1: Initializing with a Sequential Design

proc optex data=a seed=33805; model afegrsa@@2 af*af egr*egr sa*sa; generate n=saturated method=detmax; output out=b;
data c; set b; drop i; do i=1 to 5; output; end; proc optex data=a seed=33805; model afegrsa@@2 af*af egr*egr sa*sa; generate n=50 method=detmax initdesign=c; run;The results are displayed in Output 24.3.2 and Output 24.3.3. The resulting design is 99.9% Defficient and 98.3% Aefficient relative to the best design found by the straightforward approach (Output 24.2.1), and it takes considerably less time to produce.
Output 24.3.2: Efficiencies for the Unreplicated Saturated Design
Output 24.3.3: Initializing with a Data Set

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