solve_mwcsp: Solves a MWCS instance.

In mwcsr: Solvers for Maximum Weight Connected Subgraph Problem and Its Variants

Solves a MWCS instance.

Description

Generic function for solving MWCS instances using solvers collected in the package.

Usage

solve_mwcsp(solver, instance, ...)

## S3 method for class 'virgo_solver'
solve_mwcsp(solver, instance, ...)

## S3 method for class 'rmwcs_solver'
solve_mwcsp(solver, instance, max_cardinality = NULL, budget = NULL, ...)

## S3 method for class 'rnc_solver'
solve_mwcsp(solver, instance, ...)

## S3 method for class 'simulated_annealing_solver'
solve_mwcsp(solver, instance, warm_start, ...)

## S3 method for class 'scipjack_solver'
solve_mwcsp(solver, instance, ...)

Arguments

solver	a solver object returned by rmwcs_solver, annealing_solver, rnc_solver or virgo_solver.
instance	an MWCS instance, an igraph object with problem-related vertex, edge and graph attributes. See details.
...	other arguments to be passed.
max_cardinality	integer maximum number of vertices in solution.
budget	numeric maximum budget of solution.
warm_start	warm start solution, an object of the class mwcsp_solution.

Details

MWCS instance here is represented as an undirected graph, an igraph object. The package supports four types of instances: Simple MWCS, Generalized MWCS, Budget MWCS, signal MWCS problems. All the necessary weights and costs are passed by setting vertex and edge attributes. See get_instance_type to check if the igraph object is a correct MWCS instance. For Simple MWCS problem numeric vertex attribute weight must be set. For generalized version weights can be provided for edges. For budget version of the problem in addition to vertex weights it is required that igraph object would have budget_cost vertex attribute with positive numeric values.

Signal MWCS instance is quite different. There is no weight attribute for neither vertices nor edges. Instead, vertex and edge attribute signal should be provided with signal names. A numeric vector containing weights for the signals should be assigned to graph attribute signals.

See vignette for description of the supported problems. See igraph package documentation for more details about getting/setting necesasry attributes.

Value

An object of class mwcsp_solution consisting of resulting subgraph, its weight and other information about solution provided.

Examples

library(igraph)

# for a MWCS instance

data(mwcs_example)
head(V(mwcs_example)$weight)

# for a GMWCS instance
data(gmwcs_example)
head(E(gmwcs_example)$weight)

# for a SGMWCS instance
data(sgmwcs_example)
head(V(sgmwcs_example)$signal)
head(E(sgmwcs_example)$signal)

head(sgmwcs_example$signals)

mwcsr documentation built on Sept. 11, 2024, 7:49 p.m.