Parameters
Table below list the VRPSolver parameters available to the user. In addition the user may provide the following information to improve the solver performance.
- Designation of the first main resource which will be used for the bi-directional labelling.
- Priorities for branching strategies.
- Distance matrix between elementarity sets for defining initial $ng$-sets and for local search heuristic separation of $l$-row rank-1 cuts with $l\geq 5$.
Parameter | Description | Default value |
---|---|---|
GlobalTimeLimit | User time limit for the execution | 21474836 seconds |
MaxNbOfBBtreeNodeTreated | Max number of nodes in the b&b tree | 100000 |
RCSPstopCutGenTimeThresholdInPricing | Time threshold for the labeling algorithm | 10 seconds |
RCSPhardTimeThresholdInPricing | Time threshold for the labeling algorithm | 20 seconds |
RCSPnumberOfBucketsPerVertex | Calculation of step size for buckets | 25 |
RCSPdynamicBucketSteps | Calculation of step size for buckets | 1 (on) |
RCSPuseBidirectionalSearch | Bi-directional search | 2 |
RCSPapplyReducedCostFixing | Bucket arc elimination | 1 (on) |
RCSPmaxNumOfColsPerExactIteration | Max. # of generated columns per iteration | 150 |
RCSPmaxNumOfColsPerIteration | Max. # of generated columns per iteration | 30 |
StabilizationMinPhaseOfStage | Minimum stage for stabilization | 0 (everywhere) |
RCSPmaxNumOfLabelsInEnumeration | Max. # of labels in the enumeration | 1000000 |
RCSPmaxNumOfEnumeratedSolutions | Max. # of paths in the enumeration | 1000000 |
RCSPmaxNumOfEnumSolutionsForMIP | Max. total # of enumerated paths for MIP | 10000 |
RCSPmaxNumOfEnumSolsForEndOfNodeMIP | Max. total # of enumerated paths for MIP at the end of a node | 10000 |
RCSPinitNGneighbourhoodSize | Initial size of ng-sets | 8 |
RCSPmaxNGneighbourhoodSize | Maximum size of ng-sets | 8 |
RCSPrankOneCutsMaxNumPerRound | Limited-memory rank-1 cuts parameter 1 | 100 |
RCSPrankOneCutsMaxNumRows | Limited-memory rank-1 cuts parameter 2 | 5 |
RCSPrankOneCutsMemoryType | Limited-memory rank-1 cuts parameter 3 | 2 |
RCSPallowRoutesWithSameVerticesSet | Avoid inserting routes with the same set of vertices from the same pricing into the Master LP. | true (on) |
RCSPredCostFixingFalseGap | Edge and path elimination based on a false gap FG=(UB-LB)/RCSPredCostFixingFalseGap | 0 (off) |
RCSPmaxNumOfLabelsInHeurEnumeration | Max. number of labels in the heuristic enumeration. | – (MaxTimeForRestrictedMasterIpHeur must be active) |
CutTailingOffThreshold | Cut generation tailing-off parameter 1 | 0.02 (2%) |
CutTailingOffCounterThreshold | Cut generation tailing-off parameter 2 | 3 |
SafeDualBoundScaleFactor | Numerically safe dual bound multiplier | -1 (off) |
StrongBranchingPhaseOneCandidatesNumber | Strong branching parameter for phase 1 | 100 |
StrongBranchingPhaseOneTreeSizeEstimRatio | Strong branching parameter for phase 1 | 0.3 |
StrongBranchingPhaseTwoCandidatesNumber | Strong branching parameter for phase 2 | 3 |
StrongBranchingPhaseTwoTreeSizeEstimRatio | Strong branching parameter for phase 2 | 0.1 |
MaxTimeForRestrictedMasterIpHeur | Restricted master heuristic | -1 (off) |
DivingHeurUseDepthLimit | Diving heuristic (with LDS) | -1 (off) |
MaxLDSdepth | Diving heuristic (with LDS) | 0 |
MaxLDSbreadth | Diving heuristic (with LDS) | 0 |
CallFrequencyOfRestrictedMasterIpHeur | Frequency (in terms of nodes) in which the restricted master heuristic is invoked (it is first called at the root node) | – (MaxTimeForRestrictedMasterIpHeur must be active) |
MIPemphasisInRestrictedMasterIpHeur | Set the MIP solver to concentrate on improving primal bound at the expense of improving lower bound. | – (MaxTimeForRestrictedMasterIpHeur must be active) |
MaxNumEnumSolsInRestrictedMasterIpHeur | Max. number of enumerated solutions in the restricted master heuristic. | – (MaxTimeForRestrictedMasterIpHeur must be active) |