runTPLS {multiDoE}R Documentation

Multi-Stratum Two-Phase Local Search (MS-TPLS) Algorithm

Description

This function implements the Multi-Stratum Two-Phase Local Search (MS-TPLS) algorithm described in Borrotti, Sambo, Mylona and Gilmour (2016). This algorithm is useful to obtain exact optimal multi-stratum designs through a multi-criteria approach. When using runTPLS the user must establish the search problem (structure of the experiment, number of trials, optimization criteria, etc.) and the total number of iterations of MS-TPLS. The resulting experimental designs can minimize up to six criteria simultaneously from the following: "I", "Id", "D", "Ds", "A" and "As". runTPLS is able to provide the set of solutions building the approximate Pareto front for the specified optimization problem.

Usage

runTPLS(facts, units, criteria, model, iters, ...)

Arguments

facts

A list of vectors representing the distribution of factors across strata. Each item in the list represents a stratum and the first item is the highest stratum of the multi-stratum structure of the experiment. Within the vectors, experimental factors are indicated by progressive integer from 1 (the first factor of the highest stratum) to the total number of experimental factors (the last factor of the lowest stratum). Blocking factors are differently denoted by empty vectors.

units

A list whose i-th element, n_i, is the number of experimental units within each unit at the previous stratum (i-1). The first item in the list, n_1, represents the number of experimental units in the stratum 0. The latter is defined as the entire experiment, such that n_0 = 1.

criteria

A list specifying the criteria to be optimized. It can contain any combination of:

  • “I" : I-optimality

  • “Id" : Id-optimality

  • “D" : D-optimality

  • “A" : Ds-optimality

  • “Ds" : A-optimality

  • “As" : As-optimality

More detailed information on the available criteria is given in MSOpt.

model

A string which indicates the type of model, among “main", “interaction" and “quadratic".

iters

An integer indicating the number of iterations of the MS-TPLS algorithm.

...

optional arguments (see below).

Details

Additional arguments can be specified as follows:

Value

runTPLS returns a list, whose elements are:

References

M. Borrotti and F. Sambo and K. Mylona and S. Gilmour. A multi-objective coordinate-exchange two-phase local search algorithm for multi-stratum experiments. Statistics & Computing, 2017.


[Package multiDoE version 0.9.4 Index]