Returns a specification to start this module under a supervisor.

See Supervisor.

Specs

setup(keyword()) :: GenServer.on_start()

Generates a HillClimbing GenServer process to solve the problem.

Return values If the server is successfully created and initialized, this function returns {:ok, pid}, where pid is the PID of the server. If a process with the specified server name already exists, this function returns {:error, {:already_started, pid}} with the PID of that process.

If the GenServer:init/1 callback fails with reason, this function returns {:error, reason}. Otherwise, if it returns {:stop, reason} or :ignore, the process is terminated and this function returns {:error, reason} or :ignore, respectively.

Examples

iex> options = [
      problem: %Meta.Problem{
        objective: &Meta.Functions.simple_example/1,
        variables: [
          %Meta.Problem.Variable{
            name: :x,
            constraint: %Meta.Problem.Constraint{lower_boundary: 0, higher_boundary: 10}
          }
        ],
      },
      noise_sizes: [x: 0.25],
      max_iterations: 200,
      max_consecutive_no_progress_iterations: 50
    ]
iex> Meta.HillClimbing.Solver.setup(opts)
{:ok, #PID<>}

Specs

solve(pid()) :: Meta.Problem.Solution.t()

Solves for HillClimbing the problem configured in the provided pid server.

Logs

Useful logs are used with the Logger module, regarding info of the iteration index and the solution found at that index. It is also logged when the process is finished and which cryteria was used to terminate the execution:

    15:28:26.504 mfa=Meta.HillClimbing.Solver.handle_continue/2 [info]  Solution #1: %Meta.Problem.Solution{value: 51.660402502492126, variables: [%Meta.Problem.Variable{constraint: %Meta.Problem.Constraint{higher_boundary: 10, lower_boundary: 0}, name: :x, value: 7.187517130587733}]}

    15:28:26.504 mfa=Meta.HillClimbing.Solver.handle_continue/2 [info]  Solution #2: %Meta.Problem.Solution{value: 80.21040204576592, variables: [%Meta.Problem.Variable{constraint: %Meta.Problem.Constraint{higher_boundary: 10, lower_boundary: 0}, name: :x, value: 8.956026018595855}]}

    15:28:26.504 mfa=Meta.HillClimbing.Solver.handle_continue/2 [info]  Solution #3: %Meta.Problem.Solution{value: 49.492197212573195, variables: [%Meta.Problem.Variable{constraint: %Meta.Problem.Constraint{higher_boundary: 10, lower_boundary: 0}, name: :x, value: 7.035069097924568}]}

    ...

    15:28:26.529 mfa=Meta.HillClimbing.Solver.handle_continue/2 [info]  Solution #197: %Meta.Problem.Solution{value: 6.841908964815985e-11, variables: [%Meta.Problem.Variable{constraint: %Meta.Problem.Constraint{higher_boundary: 10, lower_boundary: 0}, name: :x, value: 8.271583261272285e-6}]}

    15:28:26.529 mfa=Meta.HillClimbing.Solver.handle_continue/2 [info]  Solution #198: %Meta.Problem.Solution{value: 4.2071463961827206e-11, variables: [%Meta.Problem.Variable{constraint: %Meta.Problem.Constraint{higher_boundary: 10, lower_boundary: 0}, name: :x, value: 6.4862519193928325e-6}]}

    15:28:26.529 mfa=Meta.HillClimbing.Solver.handle_continue/2 [info]  Solution #199: %Meta.Problem.Solution{value: 5.924935935911621e-11, variables: [%Meta.Problem.Variable{constraint: %Meta.Problem.Constraint{higher_boundary: 10, lower_boundary: 0}, name: :x, value: 7.697360544960604e-6}]}

    15:28:26.529 mfa=Meta.HillClimbing.Solver.handle_continue/2 [info]  Process finished by reason: 'Maximum iterations reached: 200'!

Return values

A Meta.Problem.Solution is yielded when the process converges.

Examples

iex> options = [
      problem: %Meta.Problem{
        objective: &Meta.Functions.simple_example/1,
        variables: [
          %Meta.Problem.Variable{
            name: :x,
            constraint: %Meta.Problem.Constraint{lower_boundary: 0, higher_boundary: 10}
          }
        ],
      },
      noise_sizes: [x: 0.25],
      max_iterations: 200,
      max_consecutive_no_progress_iterations: 50
    ]
iex> {:ok, pid} = Meta.HillClimbing.Solver.setup(opts)
iex> Meta.HillClimbing.Solver.solve(pid)
%Meta.Problem.Solution{
  value: 4.2071463961827206e-11,
  variables: [
    %Meta.Problem.Variable{
      constraint: %Meta.Problem.Constraint{
        higher_boundary: 10,
        lower_boundary: 0
      },
      name: :x,
      value: 6.4862519193928325e-6
    }
  ]
}