blocksdesign (version 2.5)
Nested and Crossed Block Designs for Factorial, Fractional
Factorial and Unstructured Treatment Sets
Description
Constructs randomized nested row-and-column type block designs
with arbitrary depth of nesting for arbitrary factorial or fractional
factorial treatment designs. The treatment model can be defined
by a models.matrix formula which allows any feasible
combination of quantitative or qualitative model terms.
Any feasible design size can be defined and, where necessary,
a D-optimal swapping routine will find the best fraction for the required
design size. Blocks are nested hierarchically and the block model
for any particular level of nesting can comprise either a simple nested blocks
design or a crossed row-and-column blocks design. Block sizes
are either all equal or differ, at most, by one plot within any particular row
or column classification and any particular level of nesting. The design outputs
include a data frame showing the allocation of treatments to blocks, a table
showing block levels, the fractional design efficiency,
the achieved D-efficiency, the achieved A-efficiency
(unstructured treatments only) and A-efficiency upper bounds, where available,
for each stratum in the design. For designs with simple unstructured treatments,
a plan layout showing the allocation of treatments to blocks or to rows and
columns in the bottom stratum of the design is also given.