点给极端的因素称为“明星点。”Suppose the value of the extreme is 'A'. Then 'A=sqrt(2)' would be appropriate for a design having two factors. For fourteen factors, you need to think about a fourteen-dimensional sphere, rather than a square passing through the corners of the cube. If that were the only consideration, you would use 'A=sqrt(14)'. In fact, though, there is a criterion known as "rotatability" that dictates 'A=N^(1/4)', where 'N' is the number of points in the cube portion of the design.
14因素,一个完整的!会有2 ^ 14分的立方体。CCDESIGN函数使用一半的一部分而不是全部的阶乘,所以“N”是这个值的一半,“a”
((2 ^ 14)/ 2)^ (1/4)
ans =
9.5137
的上部分设计是通过扩展限制获得设计的最大值,缩小到单位立方体。比例因子是1/9.5137 = 0.1051设计有14个因素。
