Class: Opt::Solvers::CbcSolver

Inherits:
AbstractSolver show all
Defined in:
lib/opt/solvers/cbc_solver.rb

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from AbstractSolver

supports_semi_continuous_variables?, supports_semi_integer_variables?, supports_type?

Class Method Details

.available? ⇒ Boolean

Returns:

  • (Boolean) 


40
41
42
 
# File 'lib/opt/solvers/cbc_solver.rb', line 40

def self.available?
  defined?(Cbc)
end

.supported_types ⇒ Object 



44
45
46
 
# File 'lib/opt/solvers/cbc_solver.rb', line 44

def self.supported_types
  [:lp, :mip]
end

Instance Method Details

#solve(sense:, start:, index:, value:, col_lower:, col_upper:, obj:, row_lower:, row_upper:, offset:, verbose:, time_limit:, vars:) ⇒ Object 



4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
 
# File 'lib/opt/solvers/cbc_solver.rb', line 4

def solve(sense:, start:, index:, value:, col_lower:, col_upper:, obj:, row_lower:, row_upper:, offset:, verbose:, time_limit:, vars:, **)
  model =
    Cbc.load_problem(
      sense: sense,
      start: start,
      index: index,
      value: value,
      col_lower: col_lower,
      col_upper: col_upper,
      obj: obj,
      row_lower: row_lower,
      row_upper: row_upper,
      col_type: vars.map { |v| v.is_a?(Integer) ? :integer : :continuous }
    )

  # only pass options if set to support Cbc < 2.10.0
  options = {}
  options[:log_level] = 1 if verbose
  options[:time_limit] = time_limit if time_limit
  res = model.solve(**options)

  status =
    case res[:status]
    when :primal_infeasible
      :infeasible
    else
      res[:status]
    end

  {
    status: status,
    objective: res[:objective] + offset,
    x: res[:primal_col]
  }
end