Response Surface Method Factor Objects
- DESCRIPTION:
-
A class of factors that are generated for response surface methods.
- GENERATION:
-
This class of objects are factors in the rsm.design
Objects generated by rsm.design.
An object of class "rsm.factor" represents a single variable in an
rsm.design object.
- METHODS:
-
The class "rsm.factor" has methods for the following generic functions:
[ [<- print summary
- INHERITANCE:
-
Class "rsm.factor" does not inherit from any other class
- STRUCTURE:
-
The "rsm.factor" object is implemented as a numeric vector
with the following attributes
- scale:
-
half the distance between the cube points
- center:
-
the average of the cube points
- alpha:
-
a scaling constant for the star points
- log:
-
a logical value for whether the factor is computed on the log scale
- DETAILS:
-
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).
- SEE ALSO:
-
rsm.lm
,
rsm.design
,
as.rsm.design
,
as.rsm.factor
.