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Macros for the Design and Analysis of Experiments |
ds | is the name of the SAS data set for the constructed design. This data set contains variables for design factors. Default names are used. The default names for design factors are T1, T2, T3, and so on. |
vlst | is a list of mixture components and their constraints.
Separate information for different components
with a slash (/)
and specify each component as follows:
name loval-hival where name gives the name of the component, loval
gives the low value for the component, and hival gives
the high value for the component. If you omit loval
or hival, the defaults are 0 and 1, respectively. |
m | is the maximum order of centroid to be generated. By default, centroids of all orders are generated. |
Use the ADXXVERT macro when your mixture factors are subject to constraints of the form
DIMEN | the dimension of the face of which the corresponding point is the centroid |
DIST | the average distance from the vertices on the face to the centroid |
You can try to choose design points directly based in DIMEN and DIST, or you can use the OPTEX procedure to choose an optimal design from the set of candidate points; see Example 24.10 for a detailed example. For example, consider an experiment to study the effects of a lubricant additive on three-component lubricant blends. The additive and the three components are subject to restrictions as follows:
Mixture Component | Range of Values |
Additive (ADD) | 7% to 18% |
Component A (A) | 0% to 30% |
Component B (B) | 37% to 70% |
Component C (C) | 0% to 15% |
To construct the vertices and generalized face-centroids of the feasible region and output these points to the data set LUB, submit the following statements:
%adxgen %adxmix %adxinit %adxxvert(lub,add .07 -.18 /a -.3 /b .37 -.7 /c -.15)Since m is omitted in the ADXXVERT macro call above, centroids of all orders are generated and output to LUB.
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