Mixture Design Tutorial (Part 2 – Optimization) - Statease.info

DX7-05B-Mix-P2.doc Rev. 4/12/06When you are done looking at Help, close out the screen by pressing X at the upper-rightcorner of its screen.Click the Options button to see how you gain control over how the numericaloptimization will be performed. For example, you can change the number of cycles(searches) per optimization. If you have a very complex combination of responsesurfaces, increasing the number of cycles will give you more opportunities to find theoptimal solution. The Duplicate solution filter establishes the epsilon (minimumdifference) for eliminating essentially identical solutions. The Simplex Fractionspecifies how big the initial steps will be relative to the factor ranges. (The word“simplex” relates to the geometry of the search. For two factors the simplex is anequilateral triangle. By stepping through the three corners the program figures out thepath of steepest ascent. For more detail, go to Help and search on “numerical searchalgorithm.”)Another optimization option is to not use random starting points, but rather those in thedesign itself. However, these will be limited to 100 unless you change this default.Leave this and all other options at their default levels shown below. (PS. This screenshot shows underlined letters that show Alt keys for jumping to fields via keystrokesversus mousing.)Optimization Options Dialog BoxRunning the optimizationStart the optimization by clicking on the Solutions icon.Design-Expert 7 User’s Guide Mixture Design Tutorial – Part 2 • 7