Two Level Fractional Iterator
This iterator should present each design point in the associated fractional design until all points in the fractional design have been presented.
Checks if the coded values of the design point are in the defining relation specified by the factor numbers stored in the relation set. Suppose the designing relation is I = 124 = 135 = 2345 Then relation = setOf(setOf(1,2,4), setOf(1,3,5), setOf(2,3,4,5)).
The values in the words must be valid factor indices. That is If a design has 5 factors, then the indices must be in 1..5. With 1 referencing the first factor, 2 the 2nd, etc.
Parameters
the set of words for the defining relation.
the number of replications for the design points. Must be greater or equal to 1. If null, then the current value for the number of replications of each design point is used. Null is the default.
the sign of the generator 1.0 = I, -1.0 = -I. The default is 1.0.