Package com.hexaly.optimizer

Class HxPhase

java.lang.Object
com.hexaly.optimizer.HxPhase
public class HxPhase extends Object
Optimization phase. Since Hexal Optimizer allows lexicographic multiobjective optimization, we allow you to parameterize the time or the number of iterations to spend in optimizing each objective. When multiple objectives are declared, these objectives are optimized in lexicographic order (in the order of their declaration in the model). Thus, if k objectives 0, ..., k-1 are declared, each objective i can be optimized while maintaining the values of objectives 0, ..., i-1 previously obtained and ignoring the values of objectives i+1, ..., k-1. During such an optimization phase, objective i is called the optimized objective. At least one phase must be created to launch the optimizer. If you have only one objective to optimize, then create a phase, set the time or the number of iterations, and run the optimizer. By default, the optimized objective of a phase corresponds to the last objective declared in the model (in this case, all objectives of the model are optimized together).

  • Method Details

    • getOptimizer

      public HexalyOptimizer getOptimizer()
      Returns the Hexaly Optimizer object associated to this phase.
      Returns:
      Hexaly Optimizer object.

    • setTimeLimit

      public void setTimeLimit(int timeLimit)
      Sets the time limit of this phase in seconds. Note that the "real" time (that is, total time) spent to resolve the model is considered here (and not only the CPU time). The default time limit is set to the largest positive integer on 32 bits, that is 2^31-1 = 2,147,483,647 > 10^9. Only allowed in states HxState.Modeling or HxState.Stopped. Note that if the optimal value of an objective is found before the end of the corresponding phase, the remaining time will be transferred to the next phase.
      Parameters:
      timeLimit - Time limit in seconds.

    • getTimeLimit

      public int getTimeLimit()
      Gets the time limit of this phase in seconds.
      Returns:
      Time limit in seconds.
      See Also:

    • setIterationLimit

      public void setIterationLimit(long iterationLimit)
      Sets the number of iterations of this phase. Fixing the seed and the number of iterations of all phases ensures the reproducibility of results over several runs. The default number of iterations is set to the largest positive integer on 64 bits, that is 2^63-1 = 9,223,372,036,854,775,807 > 10^18. Only allowed in states HxState.Modeling or HxState.Stopped. Note that if the optimal value of an objective is found before the end of the corresponding phase, the remaining iterations will be transferred to the next phase.
      Parameters:
      iterationLimit - Iteration limit.

    • getIterationLimit

      public long getIterationLimit()
      Gets the number of iterations of this phase.
      Returns:
      Iteration limit.
      See Also:

    • setOptimizedObjective

      public void setOptimizedObjective(int objectiveIndex)
      Sets the optimized objective of this phase. When multiple objectives are declared, these objectives are optimized in lexicographic order (in the order of their declaration in the model). Thus, if k objectives 0, ..., k-1 are declared, each objective i can be optimized while maintaining the values of objectives 0, ..., i-1 previously obtained and ignoring the values of objectives i+1, ..., k-1. By default, the optimized objective corresponds to the last objective declared in the model. Only allowed in states HxState.Modeling or HxState.Stopped.
      Parameters:
      objectiveIndex - Index of the optimized objective.

    • getOptimizedObjective

      public int getOptimizedObjective()
      Gets the index of the optimized objective.
      Returns:
      Index of the optimized objective.
      See Also:

    • setEnabled

      public void setEnabled(boolean enabled)
      Sets the enabled status of this phase. The optimizer only optimize enabled phases. Disabling a phase can be useful when an objective has been removed from the model by HxModel.removeObjective(int). By default, a phase is enabled. Only allowed in states HxState.Modeling or HxState.Stopped.
      Parameters:
      enabled - True to enable the phase, False to disable it
      Since:
      5.0

    • isEnabled

      public boolean isEnabled()
      Returns true if the phase is enabled, False otherwise.
      Returns:
      True if phase is enabled
      Since:
      5.0

    • toString

      public String toString()
      Returns a String representation of this phase. Useful for debugging or logging purposes.
      Overrides:
      toString in class Object
      Returns:
      String representation.

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object