direct.sum {conf.design}R Documentation

Form the direct sum of designs.

Description

Constructs the direct sum of two or more designs. Each plot of one design is matched with every plot of the other. (This might also be called the Cartesian product of two designs).

Usage

direct.sum(D1, D2, ..., tiebreak=letters)

Arguments

D1 First component design.
D2 Second component design.
... Additional component designs, if any.
tiebreak Series of characters or digits to be used for breaking ties (or repeats) in the variable names in the component designs.

Details

Each plot of one design is matched with every plot of the other, and so on recursively.

Value

The direct sum of all component designs.

Side Effects

None.

See Also

conf.design, fac.design, fractionate

Examples

 # Generate a half replicate of a 2^3 x 3^2 experiment.  The factors are
 # to be A, B, C, D, E.  The fractional relation is to be I = ABC and the
 # DE effect is to be confounded with blocks.

 # First construct the 2^3 design, confounded in two blocks:
 d1 <- conf.design(c(1,1,1), p=2, treatment.names=LETTERS[1:3])

 # Next the 3^2 design, with DE confounded in blocks:
 d2 <- conf.design(c(1,1), p=3, treatment.names=LETTERS[4:5])

 # Now extract the principal block from the 2^3 design and form the direct
 # sum withthe 3^2 design
 dsn <- direct.sum(d1[d1$Blocks=="0",], d2)