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Configure CBC solver settings

Source: R/set_solver.R
set_solver_cbc.Rd

Convenience wrapper around set_solver that stores solver = "cbc" in the problem object.

This function does not solve the model. It only updates the stored solver configuration. A solver can be configured only once per problem. Calling this wrapper after any solver setter raises an error. Derive alternatives from the same problem before its first solver configuration.

Usage

set_solver_cbc(
  x,
  ...,
  solver_params = list(),
  gap_limit = NULL,
  time_limit = NULL,
  solution_limit = NULL,
  cores = NULL,
  verbose = NULL,
  log_file = NULL,
  write_log = NULL
)

Arguments

x

A Problem object.

...

Additional named solver-specific parameters. These are merged into solver_params. For example, MIPFocus = 1 for Gurobi.

solver_params

Named list of solver-specific parameters. These are merged with previously stored parameters. Rcplex parameters are validated against its supported control names; Rsymphony does not currently receive arbitrary solver-specific parameters.

gap_limit

Optional numeric value in \([0,1]\) giving the relative optimality gap for mixed-integer optimization. If NULL, the previously stored value is kept unchanged.

time_limit

Optional non-negative numeric value giving the maximum solving time in seconds. If NULL, the previously stored value is kept unchanged.

solution_limit

Optional logical flag requesting early termination after a feasible solution is found. Supported by Gurobi, CBC, and SYMPHONY, but not by CPLEX through Rcplex. If NULL, the previously stored value is kept unchanged.

cores

Optional positive integer giving the maximum number of solver threads. Currently supported by Gurobi. If NULL, the previously stored value is kept unchanged.

verbose

Optional logical flag indicating whether the solver should print log output. If NULL, the previously stored value is kept unchanged.

log_file

Optional character string giving the complete path or file name of the solver log. Currently supported by Gurobi. If NULL, the previously stored value is kept unchanged.

write_log

Optional logical flag indicating whether solver output should be written to a file. Currently supported by Gurobi. If NULL, the previously stored value is kept unchanged.

Value

An updated Problem object with CBC solver settings stored in x$data$solve_args.

See also

set_solver, solve

Examples

# Load a complete simulated planning problem.
example_data <- load_sim_multiaction()

x <- create_problem(
  pu = example_data$planning_units,
  features = example_data$features,
  dist_features = example_data$dist_features,
  cost = "cost"
)

x <- set_solver_cbc(
  x,
  gap_limit = 0.01,
  time_limit = 300,
  cores = 2,
  solution_limit = FALSE
)
#> Warning: Parameter(s) not available for solver 'cbc' through its current R interface: cores (thread control is not available through rcbc). The unsupported setting(s) will be ignored.

x$data$solve_args
#> $solver
#> [1] "cbc"
#> 
#> $gap_limit
#> [1] 0.01
#> 
#> $time_limit
#> [1] 300
#> 
#> $solution_limit
#> [1] FALSE
#> 
#> $solver_params
#> list()
#>