This class contains the LocalSolver environment. It is the main class of the LocalSolver library. Here are described the basic steps for using LocalSolver:
LSVersionfor copyright and version info.
||Delete the LocalSolver objects and release the licence token.|
||Gets the state of this LocalSolver environment.|
||Gets the model associated to this LocalSolver environment.|
||Gets the parameters of this LocalSolver environment.|
||Solves the model.|
||Compute an inconsistency core for this model.|
||Aborts the resolution previously launched using Solve().|
||Adds a new phase to this LocalSolver environment.|
||Gets the phase with the given index.|
||Gets the number of phases.|
||Gets the best solution found by the solver.|
||Gets the statistics of this LocalSolver environment.|
||Returns useful info about the search while running.|
||Export a complete environment or a model to a file.|
||Import a complete environment from a file.|
||Add a new callback for a specific event type.|
||Remove the callback for the given event type.|
||Returns a string representation of this LocalSolver environment.|
Constructs a complete LocalSolver environment and take a token license. If no token is available or if the token server is not accessible, an exception is thrown. The token license is released when the destructor of this LocalSolver environment is called.
Delete the LocalSolver objects and release the licence token. This method is automatically called when the LocalSolver object was created in a using statement (see IDisposable interface). Otherwise it must be called explicitly. It deletes the native memory used by LocalSolver and makes the LocalSolver licence available for another LocalSolver model.
Gets the state of this LocalSolver environment. This method can be called in any state. In particular, this method can be called in state
Returns: State of LocalSolver. Return type: LSState
Gets the model associated to this LocalSolver environment. Once the model is created and closed, the solver can be launched with
Returns: Model Return type: LSModel
Gets the parameters of this LocalSolver environment.
Returns: Parameters Return type: LSParam
Solves the model. This method returns only when the time limit, the iteration limit or the objective bounds are reached. The model must be closed to launch the resolution.
Compute an inconsistency core for this model. Only allowed in state
Returns: Inconsistency core Return type: LSInconsistency
Aborts the resolution previously launched using
Solve(). If no resolution was launched, this method does nothing. Called from another thread, this method enables users to stop the resolution properly. Solution and statistics remain valid. This method can be called in any state, notably in state
Adds a new phase to this LocalSolver environment. Only allowed in state
Returns: Created phase. Return type: LSPhase
Arguments: phaseId (
int) – Index of the phase
Returns: Phase Return type: LSPhase
Returns: Number of phases. Return type:
Gets the best solution found by the solver. If the solver has not been started at least once, all the decision variables of the solution are set to 0, or to their closest bound if 0 is not part of their domain (such a solution may be infeasible). Only allowed in states
Returns: The best solution. Return type: LSSolution
Gets the statistics of this LocalSolver environment. Statistics are reset to zero before each resolution. Only allowed in states
Stopped. Note that for performance reasons, this function always returns the same object.
Returns: Statistics. Return type: LSStatistics
Returns useful info about the search while running. Only allowed if the solver has been started at least once. Only allowed in states
Stopped. Useful for debugging or logging purposes. Here are some explanations about the output string:
- “sec” stands for the number of seconds.
- “itr” stands for the number of iterations.
- “infeas” corresponds to the infeasibility score of the best solution found, if infeasible.
- “obj” corresponds to the objective values of the best solution found, if feasible.
- “mov” corresponds to the number of moves performed.
- “inf” corresponds to the percentage of infeasible moves.
- “acc” corresponds to the percentage of accepted moves.
- “imp” corresponds to the number of improving moves.
Returns: Info about the search while running Return type: string
Export a complete environment or a model to a file.
Currently, this function supports 2 file formats :
- LSB : with this format, the complete environment (model, parameters, solution, ...) is exported. This format is useful to debug or replay a model in the same conditions. Since the produced file is binary, it offers good performance and space efficiency.
- LSP : with this format, only the model is exported in the LSP language. This format is useful to have a quick view of the optimization model or to perform some modifications. However, the file may be heavy for big models and the exact reproductibility is not guaranteed since the parameters from one execution to another may differ.
The chosen file format is determined by the file suffix. An exception is thrown if the provided file suffix is not supported. The suffix may optionally be followed by .gz. In that case, this function produces a compressed result (using deflate algorithm).
Arguments: filename (string) – Name of the file. Since: 3.0
Import a complete environment from a file. Only allowed in state
Modeling. The current model must be empty.
The only format supported is LSB. You can obtain a such file thanks to
The chosen file format is determined by the file suffix. An exception is thrown if the provided file suffix is not supported. The suffix may optionally be followed by .gz. In that case, this function uncompress the stream before reading.
Arguments: filename (string) – Name of the file. Since: 3.0
AddCallback(LSCallbackType type, LSCallback callback)¶
Add a new callback for a specific event type. The callback will be called each time the given event occurs. When a callback is called, the solver is paused. You can stop the resolution from a callback, retrieve the current solution, retrieve the statistics of the solver and, in general, call all the methods marked as “allowed in state
The same callback can be used for different events.
The callback delegate must accept 2 parameters that are respectively the LocalSolver environment and the type of the event.
RemoveCallback(LSCallbackType type, LSCallback callback)¶
Remove the callback for the given event type.
False if the callback was not added for the given event, True otherwise.
Returns a string representation of this LocalSolver environment. This representation provides useful info related to the model, the parameters, and the phases (if any). Useful for debugging or logging purposes.
Returns: String representation of this LocalSolver. Return type: string