LSParam Class

class localsolver.LSParam

Solving parameters. This class contains some methods allowing you to parameterize the resolution of the model. For the sake of simplicity, only a few parameters are actually offered to tune the search.

Summary

Methods

GetLocalSolver

Returns the LocalSolver object associated to these parameters.

SetSeed

Sets the seed of the pseudo-random number generator used by the solver.

GetSeed

Gets the seed of the pseudo-random number generator used by the solver.

SetNbThreads

Sets the number of threads used to parallelize the search.

GetNbThreads

Gets the number of threads.

SetTimeLimit

Sets the time limit in seconds.

GetTimeLimit

Gets the time limit in seconds.

SetIterationLimit

Sets the maximum number of iterations.

GetIterationLimit

Gets the maximum number of iterations.

SetAnnealingLevel

Sets the simulated annealing levelDeprecated since version 8.5: The annealing level doesn’t have a significant influence on the search anymore.

GetAnnealingLevel

Gets the simulated annealing levelDeprecated since version 8.5: The annealing level doesn’t have a significant influence on the search anymore.

SetVerbosity

Sets the verbosity level of the solver.

GetVerbosity

Gets the verbosity level of the solver.

SetTimeBetweenDisplays

Sets the time in seconds between two consecutive displays in console while the solver is running.

GetTimeBetweenDisplays

Gets the time in seconds between two consecutive displays in console while the solver is running.

SetTimeBetweenTicks

Sets the time in seconds between two events of type LSCallbackType.TimeTicked.

GetTimeBetweenTicks

Gets the time in seconds between two events of type LSCallbackType.TimeTicked.

SetIterationBetweenTicks

Sets the number of iterations between two events of type LSCallbackType.IterationTicked.

GetIterationBetweenTicks

Gets the number of iterations between two events of type LSCallbackType.IterationTicked.

SetLogWriter

Sets the writer used by LocalSolver for its logging.

GetLogWriter

Returns the writer used by LocalSolver for its logging.

SetLogFile

Sets the path of the LocalSolver log file.

GetLogFile

Returns the path of the LocalSolver log file.

SetObjectiveThreshold

Sets the threshold of the objective with the given index.

SetIntObjectiveThreshold

Sets the threshold of the objective with the given index.

SetDoubleObjectiveThreshold

Sets the threshold of the objective with the given index.

GetObjectiveThreshold

Gets the threshold of the objective with the given index.

GetIntObjectiveThreshold

Gets the threshold of the objective with the given index.

GetDoubleObjectiveThreshold

Gets the threshold of the objective with the given index.

SetAdvancedParam

Reserved for maintenance purpose.

GetAdvancedParam

Reserved for maintenance purpose.

ToString

Returns a string representation of these parameters.

Instance methods

LocalSolver GetLocalSolver()

Returns the LocalSolver object associated to these parameters.

Returns:

LocalSolver object

Return type:

LocalSolver

void SetSeed(int seed)

Sets the seed of the pseudo-random number generator used by the solver. The seed must be a positive integer. The default seed is set to 0. Only allowed in states Modeling or Stopped.

Arguments:

seed (int) – Seed of the pseudo-random number generator.

int GetSeed()

Gets the seed of the pseudo-random number generator used by the solver.

Returns:

Seed of the pseudo-random number generator.

See:

LSParam.SetSeed

void SetNbThreads(int nbThreads)

Sets the number of threads used to parallelize the search. The number of threads must be a positive integer. The default number of threads is set to 0 which means that the number of threads is automatically adapted to your computer and to your optimization model. Only allowed in states Modeling or Stopped.

This parameter is indicative, if needed LocalSolver may use more threads. The actual number of threads can also vary during the search.

Arguments:

nbThreads (int) – Number of threads.

int GetNbThreads()

Gets the number of threads. By convention, value 0 means that the number of threads is automatically adapted to your computer and to your optimization model.

Returns:

Number of threads.

See:

LSParam.SetNbThreads

void SetTimeLimit(int timeLimit)

Sets the time limit in seconds. Only allowed in states Modeling or Stopped.

This is not allowed if you have defined multiple phases. Use LSPhase.SetTimeLimit to set the limit for each phase instead.

Arguments:

timeLimit (int) – Time limit in seconds.

See:

LSPhase

int GetTimeLimit()

Gets the time limit in seconds.

This is not allowed if you have defined multiple phases. Use LSPhase.GetTimeLimit instead.

Returns:

Time limit in seconds.

See:

LSParam.SetTimeLimit

See:

LSPhase

void SetIterationLimit(long iterationLimit)

Sets the maximum number of iterations. Only allowed in states Modeling or Stopped.

Arguments:

iterationLimit (long) – Iteration limit.

See:

LSPhase

long GetIterationLimit()

Gets the maximum number of iterations.

Returns:

Iteration limit.

See:

LSParam.SetIterationLimit

See:

LSPhase

void SetAnnealingLevel(int annealingLevel)

Sets the simulated annealing level

Deprecated since version 8.5: The annealing level doesn’t have a significant influence on the search anymore. The tuning of this parameter won’t be allowed in a future version.

The level must be an integer between 0 and 9. The default simulated annealing level is set to 1. Only allowed in states Modeling or Stopped.

Arguments:

annealingLevel (int) – Simulated annealing level.

int GetAnnealingLevel()

Gets the simulated annealing level

Deprecated since version 8.5: The annealing level doesn’t have a significant influence on the search anymore. The tuning of this parameter won’t be allowed in a future version.

Returns:

Simulated annealing level.

See:

LSParam.SetAnnealingLevel

void SetVerbosity(int verbosity)

Sets the verbosity level of the solver. The default verbosity is set to 1. Only allowed in states Modeling or Stopped. There are 3 defined verbosity levels:

  • 0: All the traces are disabled.

  • 1: Normal verbosity. This is the default level.

  • 2: Detailed verbosity. Displays statistics during the search.

Arguments:

verbosity (int) – Verbosity level: 0, 1, 2.

int GetVerbosity()

Gets the verbosity level of the solver.

Returns:

verbosity Verbosity level: 0, 1 or 2.

See:

LSParam.SetVerbosity

void SetTimeBetweenDisplays(int timeBetweenDisplays)

Sets the time in seconds between two consecutive displays in console while the solver is running. The default time between displays is set to 1 second. Only allowed in states Modeling or Stopped.

Arguments:

timeBetweenDisplays (int) – Time in seconds between displays.

int GetTimeBetweenDisplays()

Gets the time in seconds between two consecutive displays in console while the solver is running.

Returns:

Time in seconds between displays.

Return type:

int

See:

LSParam.SetTimeBetweenDisplays

void SetTimeBetweenTicks(int timeBetweenTicks)

Sets the time in seconds between two events of type LSCallbackType.TimeTicked. The default time between ticks is set to 1 second. Only allowed in states Modeling or Stopped.

Since:

6.0

Arguments:

timeBetweenTicks (int) – Time in seconds between ticks.

int GetTimeBetweenTicks()

Gets the time in seconds between two events of type LSCallbackType.TimeTicked.

Since:

6.0

Returns:

Time in seconds between ticks.

See:

LSParam.SetTimeBetweenTicks

void SetIterationBetweenTicks(long iterationBetweenTicks)

Sets the number of iterations between two events of type LSCallbackType.IterationTicked. The default number of iterations between ticks is set to 10,000. Only allowed in states Modeling or Stopped.

Since:

6.0

Arguments:

iterationBetweenTicks (long) – Number of iterations between ticks.

long GetIterationBetweenTicks()

Gets the number of iterations between two events of type LSCallbackType.IterationTicked.

Since:

6.0

Returns:

Number of iterations between ticks.

See:

LSParam.SetIterationBetweenTicks

void SetLogWriter(System.IO.TextWriter writer)

Sets the writer used by LocalSolver for its logging. The default is to log to the standard output. To tune the logging verbosity of the output, see SetVerbosity. Note that you can specify both the log writer and the log file by using the method SetLogFile.

Arguments:

writer – Writer for the logging or null to disable logging.

Since:

9.5

System.IO.TextWriter GetLogWriter()

Returns the writer used by LocalSolver for its logging. The default value is initialized to the standard output, retrieved with Console.Out. If no console is available, logging is disabled.

To tune the logging verbosity of the output, see SetVerbosity.

Returns:

The writer used by LocalSolver for its logging or null if logging is disabled.

Since:

9.5

void SetLogFile(string path)

Sets the path of the LocalSolver log file. If the path is empty, no log will be saved. To tune the logging verbosity, see LSParam.SetVerbosity. Only allowed in states Modeling or Stopped.

Arguments:

path (string) – Path of the log file. Leave empty to disable the logging mechanism.

See:

LSParam.SetVerbosity

See:

LSParam.GetLogFile

string GetLogFile()

Returns the path of the LocalSolver log file. If no log file was specified, an empty string is returned.

Returns:

The path of the log file or an empty string.

See:

LSParam.SetLogFile

void SetObjectiveThreshold(int objectiveIndex, long threshold)

Sets the threshold of the objective with the given index. If the objective is minimized (resp. maximized), then the optimization of this objective is stopped as soon as this lower (resp. upper) threshold is reached. It can be useful for goal programming. Only allowed in states Stopped.

This method has the same behavior as LSParam.SetIntObjectiveThreshold.

Since:

8.5

Arguments:
  • objectiveIndex (int) – Index of the objective.

  • threshold (long) – Objective threshold.

See:

LSExpression.IsObjective

See:

LSExpression.IsInt

void SetObjectiveThreshold(int objectiveIndex, double threshold)

Sets the threshold of the objective with the given index. If the objective is minimized (resp. maximized), then the optimization of this objective is stopped as soon as this lower (resp. upper) threshold is reached. It can be useful for goal programming. Only allowed in states Stopped.

This method has the same behavior as LSParam.SetDoubleObjectiveThreshold.

Since:

8.5

Arguments:
  • objectiveIndex (int) – Index of the objective.

  • threshold (double) – Objective threshold.

See:

LSExpression.IsObjective

See:

LSExpression.IsDouble

void SetIntObjectiveThreshold(int objectiveIndex, long threshold)

Sets the threshold of the objective with the given index. If the objective is minimized (resp. maximized), then the optimization of this objective is stopped as soon as this lower (resp. upper) threshold is reached. It can be useful for goal programming. Only allowed in states Stopped.

Since:

8.5

Arguments:
  • objectiveIndex (int) – Index of the objective.

  • threshold (long) – Objective threshold.

See:

LSExpression.IsObjective

See:

LSExpression.IsInt

void SetDoubleObjectiveThreshold(int objectiveIndex, double threshold)

Sets the threshold of the objective with the given index. If the objective is minimized (resp. maximized), then the optimization of this objective is stopped as soon as this lower (resp. upper) threshold is reached. It can be useful for goal programming. Only allowed in states Stopped.

Since:

8.5

Arguments:
  • objectiveIndex (int) – Index of the objective.

  • threshold (double) – Objective threshold.

See:

LSExpression.IsObjective

See:

LSExpression.IsDouble

long GetObjectiveThreshold(int objectiveIndex)

Gets the threshold of the objective with the given index. Only allowed in states Paused or Stopped.

Since:

8.5

Arguments:

objectiveIndex (int) – Index of the objective.

Returns:

Objective threshold.

Return type:

long

See:

LSParam.SetObjectiveThreshold(int, long)

long GetIntObjectiveThreshold(int objectiveIndex)

Gets the threshold of the objective with the given index. Only allowed in states Paused or Stopped.

Since:

8.5

Arguments:

objectiveIndex (int) – Index of the objective.

Returns:

Objective threshold.

Return type:

long

See:

LSParam.SetIntObjectiveThreshold

double GetDoubleObjectiveThreshold(int objectiveIndex)

Gets the threshold of the objective with the given index. Only allowed in states Paused or Stopped.

Since:

8.5

Arguments:

objectiveIndex (int) – Index of the objective.

Returns:

Objective threshold.

Return type:

double

See:

LSParam.SetDoubleObjectiveThreshold

void SetAdvancedParam(string key, int value)

Reserved for maintenance purpose.

Sets the value of an advanced parameter. Advanced parameters are reserved for fine tuning or debugging and should not be used by end-users. Only allowed in states Modeling or Stopped.

Arguments:
  • key – Name of the parameter.

  • value – Value of the parameter.

int GetAdvancedParam(string key)

Reserved for maintenance purpose.

Returns the value of an advanced parameter. Advanced parameters are reserved for fine tuning or debugging and should not be used by end-users. Throws an exception if the parameter does not exist.

Arguments:

key – Name of the parameter.

Returns:

Value of the parameter.

See:

LSParam.SetAdvancedParam(string, int)

int GetAdvancedParam(string key, int defaultValue)

Reserved for maintenance purpose.

Returns the value of an advanced parameter. Advanced parameters are reserved for fine tuning or debugging and should not be used by end-users. The default value is returned if the parameter does not exist or if no value was set for this one.

Arguments:
  • key (string) – Name of the parameter.

  • defaultValue (int) – Default value of the parameter.

See:

LSParam.SetAdvancedParam(string, int)

void SetAdvancedParam(string key, double value)

Reserved for maintenance purpose.

Sets the value of an advanced parameter. Advanced parameters are reserved for fine tuning or debugging and should not be used by end-users. Only allowed in states Modeling or Stopped.

Arguments:
  • key – Name of the parameter.

  • value – Value of the parameter.

double GetAdvancedParam(string key, double defaultValue)

Reserved for maintenance purpose.

Returns the value of an advanced parameter. Advanced parameters are reserved for fine tuning or debugging and should not be used by end-users. The default value is returned if the parameter does not exist or if no value was set for this one.

Arguments:
  • key (string) – Name of the parameter.

  • defaultValue (double) – Default value of the parameter.

See:

LSParam.SetAdvancedParam(string, double)

void SetAdvancedParam(string key, string value)

Reserved for maintenance purpose.

Sets the value of an advanced parameter. Advanced parameters are reserved for fine tuning or debugging and should not be used by end-users. Only allowed in states Modeling or Stopped.

Arguments:
  • key (string) – Name of the parameter.

  • value (string) – Value of the parameter.

string GetAdvancedParam(string key, string defaultValue)

Reserved for maintenance purpose.

Returns the value of an advanced parameter. Advanced parameters are reserved for fine tuning or debugging and should not be used by end-users. The default value is returned if the parameter does not exist or if no value was set for this one.

Arguments:
  • key (string) – Name of the parameter.

  • defaultValue (string) – Default value of the parameter.

See:

LSParam.SetAdvancedParam(string, string)

string ToString()

Returns a string representation of these parameters. Useful for debugging or logging purposes.

Returns:

String representation.