rsm.factor from a Vector
rsm.factor
, for use with fitting response surface methods.
as.rsm.factor(x, logx = F)
rsm.factor is spaced on the log scale
rsm.factor, a vector with the following attributes:
If
x has 3 or 5 unique values the returned value is computed as follows.
The cube points, a and b, of the vector
x
are taken as the second and fourth
unique ordered value of
x (first and third if there are 3 values). The
star points, c and d are the first and fifth unique ordered values
of
x (first and third if there are 3 values). Then
scale
= (b-a)/2, center = (a+b)/2,
and
alpha = (d - "center")/("center" - a).
For any other number of unique values,
alpha = 1;
scale =
(max(x)-min(x))/2;
center = min(x)+
scale.
In this case the
scaled
rsm.factor (as used in
rsm.lm) will have min = -1 and max = 1.