Class PropagationGuidedNeighborhood

  • All Implemented Interfaces:
    ICause, INeighbor
    Direct Known Subclasses:

    public class PropagationGuidedNeighborhood
    extends IntNeighbor
    A Propagation Guided LNS

    Based on "Propagation Guided Large Neighborhood Search", Perron et al. CP2004.

    Charles Prud'homme
    • Field Detail

      • n

        protected final int n
        Number of variables
      • rd

        protected Random rd
        For randomness
      • all

        protected int[] all
        Store the modified variables
      • fragment

        protected BitSet fragment
        Indicate which variables are selected in a fragment
      • mModel

        protected Model mModel
        Reference to the model
    • Constructor Detail

      • PropagationGuidedNeighborhood

        public PropagationGuidedNeighborhood​(IntVar[] vars,
                                             int fgmtSize,
                                             int listSize,
                                             long seed)
        Create a propagation-guided neighbor for LNS
        vars - set of variables to consider
        fgmtSize - initial size of the fragment
        listSize - number of modified variable to store while propagating
        seed - for randomness
    • Method Detail

      • fixSomeVariables

        public void fixSomeVariables()
                              throws ContradictionException
        Description copied from interface: INeighbor
        Freezes some variables in order to have a fast computation. The fixed variables are declared as decisions in the decision path.
      • restrictLess

        public void restrictLess()
        Description copied from interface: INeighbor
        Use less restriction at the beginning of a LNS run in order to get better solutions Called when no solution was found during a LNS run (trapped into a local optimum)
      • init

        public void init()
        Description copied from interface: INeighbor
        Initialize this neighbor