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First-improvement local search, with automatic VNMI dispatch for n > 300.

Source: R/lcda_grasp.R
lcda_local_search.Rd

First-improvement local search, with automatic VNMI dispatch for n > 300.

Usage

lcda_local_search(
  csr,
  construction,
  centrality = "eigen",
  n_threshold = 300,
  vnmi_n_prime = 300,
  vnmi_eps = 1e-04,
  verbose = FALSE
)

Arguments

csr

a CSR list (indptr, indices, igraph) from the internal converter.

construction

a list as returned by [lcda_construct()]/[lcda_repair()].

centrality

leader-selection centrality passed on to [lcda_repair()] so the re-validated leader matches the chosen measure.

n_threshold

node count above which VNMI is used instead of full search.

vnmi_n_prime

size of the sampled subset V' used by VNMI.

vnmi_eps

minimum per-move modularity gain accepted by VNMI.

verbose

logical; emit a cli trace.

Value

the input `construction` with updated `membership`, `Q`, and leaders.

See also

[as_csr()], [lcda_construct()], [lcda_repair()].

Examples

csr <- as_csr(igraph::make_graph("Zachary"))
sol <- lcda_local_search(csr, lcda_construct(csr, 0.1, 0.3))
sol$Q                          # modularity after local search
#> [1] 0.3717949