Pre-build Edge-Weight Lookup Matrices

Constructs one n x n matrix per objective so that the weight of any edge (i, j) can be queried in O(1) via standard matrix indexing.

Usage

build_weight_lookup(instance, n, num_obj)

Arguments

instance

data.frame returned by generate_instance or one with columns from, to, weight_1, weight_2 (and optionally weight_3).

n

Integer. Number of nodes.

num_obj

Integer. Number of objectives (2 or 3).

Value

A list of length num_obj; element k is the symmetric n x n weight matrix of objective k.

Examples

inst <- generate_instance(10, 2, seed = 1)
L <- build_weight_lookup(inst, 10, 2)
L[[1]][1, 2]
#> [1] 33.89578