For the option: | Do the following: |
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Controls | |
Hierarchy | Select one of the following: ■None: Stepwise refinement adds or removes terms regardless of the other terms that are in the polynomial. For example, stepwise refinement may remove the term x1 while leaving x12. Stepwise refinement will never remove the constant term. ■Preserve Factors: If a term is active, then all mathematical factors of the term are also active. For example, if x1*x22 is active, then x1, x2, x222, and x1*x2 must all also be active. This preserves variable offsets, such that offsetting a variable does not change the form of the polynomial. ■Preserve Term Order: If a term of a particular order in a particular variable is active, then all other terms of that order that include that variable must also be active. In effect, this applies linear/quadratic/cubic settings on each variable so that each variable may be a different order. For example, the refined regression may be quadratic in x1 but only linear in x2. In this case, all quadratic x1 terms and all linear x2 terms are included. ■Preserve Polynomial Order: This selects linear, quadratic, or cubic for the entire polynomial. This preserves variable rotations, such that rotating or linearly recombining variables doesn't change the form of the polynomial. Note: These hierarchy options are in order of decreasing flexibility and computational time. No hierarchy allows the most flexibility, but takes the longest to run and may produce a polynomial that does not make intuitive sense. Preserving polynomial order is the least flexible, but runs quickly and produces the most well-rounded polynomial. |
Criteria | Select one of the following: ■P: Adams Insight includes terms or sets of terms that have a P value less than the threshold entered below. ■F: Adams Insight includes terms or sets of terms that have an F value greater than the threshold entered below. |
Threshold | Enter the threshold on which the criteria (above) is based. |
Cache | Select the type of information to cache. For most experiments, you can select both cache options. Adams Insight stores intermediate results during the refinement and, in most cases, will greatly speed up the refinement process. The data storage does take computer memory, however, so it is possible that for some very large models it will be necessary to turn one or both off. If it is necessary to turn one option off, turn off the Term caching as it takes the most memory. |
Monitor | |
Messages | Select the type of messages you want to view during the refinement process. |