Produces a star point design of experiments
a 1-by-1 matrix of doubles, positive integer, the number of variables of the experiments
a 1-by-n matrix of strings. The options are "alpha" and "center".
a 1-by-n matrix of strings. If "Name"=="alpha", "Parameter" can be "orthogonal", "rotatable" or "faced" (default). If "Name"=="center", then "Parameter" is a 1-by-2 row vector of doubles, positive integers, indicating the number of center points assigned in each block of the response surface design. Default is [1 1]. See "Description" for more details.
a 2*nbvar-by-nbvar matrix of doubles, the design of experiments
a 1-by-1 matrix of doubles, a positive integer, the value of alpha
The function computes a star points design of experiments, used as an additional block of runs in Response Surface Designs (RSM). Each factor is sequentially placed at +/-alpha, while all other factors are at zero. The value of alpha is determined by the user to give the design desirable properties.
A RSM design includes a factorial block of exeprimental runs and a block of center points.These points are used to calculate alpha, as follows: If the design is orthogonal, alpha = sqrt(nbvar*(1+(nao/na))/(1+(nco/nc))), nc the factorial points, nco the center points added to the factorial design, na the axial points, nao the center points added to the axial points. If the design is rotatable, alpha = nc^1/4, where nc=2^nbvar are the factorial points. If the design is faced, then alpha=1.
The center points is a 1-by-2 row vector of doubles, positive integers, indicating the number of center points assigned in each block of the response surface design. The default number of center points is [1,1], meaning 1 center point in the factorial block of the doe and 1 center point in the star points block. Seting the number of center points is meaningful only for the "orthogonal" design.
// Star points placed on the face of a factorial design H = scidoe_star(3) or H = scidoe_star(3,"alpha","faced") // Star points block for orthogonal design with 3 factors H = scidoe_star(3,"alpha","orthogonal") // Star points block for rotatable design with 3 factors H = scidoe_star(3,"alpha,"rotatable") // Star doe with 2 center points in the factorial block and 3 center points in the star points block H = scidoe_star(3,"alpha","orthogonal","center",[2 3]) | ![]() | ![]() |
http://en.wikipedia.org/wiki/Central_composite_design
http://www.itl.nist.gov/div898/handbook/pri/section3/pri3361.htm