Choice of simplex method

Be flexible in the choice of simplex method. It can be difficult to state a priori which method will be the preferred in a given situation. If a reflected vertex should give a considerable improvement, it would be natural to try an experiment in an extended vertex. 

The Basic simplex method is good when the experimental domain is not too large. 

If prior knowledge of the influence of the variables is available, the size of the simplex can be chosen to give a good progression along the path of the steepest ascent. Close to an optimum, the simplex will encircle the optimum conditions. As these experimental points are evenly distributed, they can be incorporated in a equiradial design (see Chapter 12) which can be used to fit a response surface model in the optimum domain. 

Carlson, L. Hansson and T. Lundstedt Acta Chem. Scand b 40 (1986) 444. 

Optimization via Simplex. Part I. Background, Definitions and Simple Application Intell. Lab. Syst. 1 (19S7) 135. 

---