LSStatistics Class¶

class localsolver.LSStatistics¶: Statistics of the search. The statistics are useful for evaluating the quality of your model. Indeed, your model is suited for LocalSolver (and more generally for local search) if the percentage of accepted moves is larger than 1 % with an annealing level equal to 0. Larger is the percentage of accepted moves, larger is the diversification of the search, better is the convergence toward high-quality solutions. If the number of accepted moves is too low, we suggests you to relax some constraints of the model (goal programming) or to augment the annealing level. A fine modeling is much preferable to a fine tuning of the search, both for effectiveness and for robustness.

Summary¶

Methods¶
`get_running_time`	Gets the running time in seconds.
`get_nb_iterations`	Gets the number of iterations.
`get_nb_moves`	Gets the number of (attempted) moves.
`get_nb_accepted_moves`	Gets the number of accepted moves.
`get_nb_improving_moves`	Gets the number of accepted moves having improved the cost of the current solution.
`get_nb_rejected_moves`	Gets the number of rejected moves.
`get_nb_infeasible_moves`	Gets the number of moves leading to infeasible solutions.
`get_percent_accepted_moves`	Gives the percentage of accepted moves relative to the number of moves.
`get_percent_improving_moves`	Gives the percentage of improving moves relative to the number of moves.
`get_percent_rejected_moves`	Gives the percentage of rejected moves relative to the number of moves.
`get_percent_infeasible_moves`	Gives the percentage of infeasible moves relative to the number of moves.
`get_info`	Returns useful info about the search while running.

Attributes¶
`running_time`	Running time in seconds.
`nb_iterations`	Number of iterations.
`nb_moves`	Number of attempted moves.
`nb_accepted_moves`	Number of accepted moves.
`nb_improving_moves`	Number of improving moves.
`nb_rejected_moves`	Number of rejected moves.
`nb_infeasible_moves`	Number of infeasible moves.
`percent_accepted_moves`	Percentage of accepted moves relative to the number of moves.
`percent_improving_moves`	Percentage of improving moves relative to the number of moves.
`percent_rejected_moves`	Percentage of rejected moves relative to the number of moves.
`percent_infeasible_moves`	Percentage of infeasible moves relative to the number of moves.
`info`	Useful info about the search.

Special methods¶
`__str__`	Returns a string representation of the statistics.

Instance methods¶

LSStatistics.get_running_time()¶

Gets the running time in seconds. Note that is the “real” time spent (and not only the CPU or system time). Only allowed in states LSState.PAUSED or LSState.STOPPED.

You can also use the shortcut member running_time

Returns:	Running time in seconds
Return type:	int

LSStatistics.get_nb_iterations()¶

Gets the number of iterations. Only allowed in states LSState.PAUSED or LSState.STOPPED.

You can also use the shortcut member nb_iterations

Returns:	Number of iterations.
Return type:	int

LSStatistics.get_nb_moves()¶

Gets the number of (attempted) moves. This corresponds to the number of explored solutions (feasible or infeasible). Only allowed in states LSState.PAUSED or LSState.STOPPED.

You can also use the shortcut member nb_moves

Returns:	Number of (attempted) moves.
Return type:	int

LSStatistics.get_nb_accepted_moves()¶

Gets the number of accepted moves. Only allowed in states LSState.PAUSED or LSState.STOPPED.

You can also use the shortcut member nb_accepted_moves

Returns:	Number of accepted moves.
Return type:	int

LSStatistics.get_nb_improving_moves()¶

Gets the number of accepted moves having improved the cost of the current solution. Improving moves are a part of accepted moves. Only allowed in states LSState.PAUSED or LSState.STOPPED.

Returns:	Number of improving moves.
Return type:	int

LSStatistics.get_nb_rejected_moves()¶

Gets the number of rejected moves. Only allowed in states LSState.PAUSED or LSState.STOPPED.

You can also use the shortcut member nb_rejected_moves

Returns:	Number of rejected moves.
Return type:	int

LSStatistics.get_nb_infeasible_moves()¶

Gets the number of moves leading to infeasible solutions. Infeasible moves are a part of rejected moves. Only allowed in states LSState.PAUSED or LSState.STOPPED.

You can also use the shortcut member nb_infeasible_moves

Returns:	Number of infeasible moves.
Return type:	int

LSStatistics.get_percent_accepted_moves()¶

Gives the percentage of accepted moves relative to the number of moves. Only allowed in states LSState.PAUSED or LSState.STOPPED.

You can also use the shortcut member percent_accepted_moves

Returns:	Percentage of accepted moves.
Return type:	double

LSStatistics.get_percent_improving_moves()¶

Gives the percentage of improving moves relative to the number of moves. Only allowed in states LSState.PAUSED or LSState.STOPPED.

You can also use the shortcut member percent_improving_moves

Returns:	Percentage of improving moves.
Return type:	double

LSStatistics.get_percent_rejected_moves()¶

Gives the percentage of rejected moves relative to the number of moves. Only allowed in states LSState.PAUSED or LSState.STOPPED.

You can also use the shortcut member percent_rejected_moves

Returns:	Percentage of rejected moves.
Return type:	double

LSStatistics.get_percent_infeasible_moves()¶

Gives the percentage of infeasible moves relative to the number of moves. Only allowed in states LSState.PAUSED or LSState.STOPPED.

You can also use the shortcut member percent_infeasible_moves

Returns:	Percentage of infeasible moves.
Return type:	double

LSStatistics.get_info()¶

Returns useful info about the search while running. Only allowed if the solver has been started at least once. Only allowed in states LSState.PAUSED or LSState.STOPPED. Useful for debugging or logging purposes.

Here are some explanations about the output string:

“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:	str

Instance attributes¶

All get/set methods have their attribute counterpart. You can use them as shortcuts to improve the readability or your models and codes.

LSStatistics.running_time¶: Running time in seconds. This attribute is read-only. It is a shortcut for get_running_time().

LSStatistics.nb_iterations¶: Number of iterations. This attribute is read-only. It is a shortcut for get_nb_iterations().

LSStatistics.nb_moves¶: Number of attempted moves. This attribute is read-only. It is a shortcut for get_nb_moves().

LSStatistics.nb_accepted_moves¶: Number of accepted moves. This attribute is read-only. It is a shortcut for get_nb_accepted_moves().

LSStatistics.nb_improving_moves¶: Number of improving moves. This attribute is read-only. It is a shortcut for get_nb_improving_moves().

LSStatistics.nb_rejected_moves¶: Number of rejected moves. This attribute is read-only. It is a shortcut for get_nb_rejected_moves().

LSStatistics.nb_infeasible_moves¶: Number of infeasible moves. This attribute is read-only. It is a shortcut for get_nb_infeasible_moves().

LSStatistics.percent_accepted_moves¶: Percentage of accepted moves relative to the number of moves. This attribute is read-only. It is a shortcut for get_percent_accepted_moves().

LSStatistics.percent_improving_moves¶: Percentage of improving moves relative to the number of moves. This attribute is read-only. It is a shortcut for get_percent_improving_moves().

LSStatistics.percent_rejected_moves¶: Percentage of rejected moves relative to the number of moves. This attribute is read-only. It is a shortcut for get_percent_rejected_moves().

LSStatistics.percent_infeasible_moves¶: Percentage of infeasible moves relative to the number of moves. This attribute is read-only. It is a shortcut for get_percent_infeasible_moves().

LSStatistics.info¶: Useful info about the search. This attribute is read-only. It is a shortcut for get_info().

Special operators and methods¶

LSStatistics.__str__()¶

Returns a string representation of the statistics. Only allowed in states LSState.PAUSED or LSState.STOPPED. Useful for debugging or logging purposes.

Returns:	String representation.
Return type:	str