Hi everybody<br><br>I have got a problem which is decomposed and uses DIP for testing the numerical behaviour under B&C&P(doPriceCut) and doCut.<br><br>branch and price log is the folloinwg which declares infeasibility:<br>
Model core nCols= 35 nRows = 99<br>== Welcome to the Abstract Library for Parallel Search (ALPS)<br>== Copyright 2000-2011 Lehigh University and others<br>== All Rights Reserved.<br>== Distributed under the Eclipse Public License 1.0<br>
== Version: Trunk (unstable)<br>== Build Date: Jul 2 2012<br>Alps0250I Starting search ...<br>Process Node 0 (algo = PRICE_AND_CUT, phaseLast = PHASE_UNKNOWN) gLB = -INF gUB = INF gap = INF time = 1.560<br>phase = PHASE_PRICE1<br>
Processing Node 0 algo= PRICE_AND_CUT phase= PHASE_PRICE1 c= 0 p= 1 LB= -1.000 UB= 9.000 nodeLB= -1.000 gLB= -1.000 gUB=<br> INF lpGap= 10.000 ipGap= INF time= 1.66<br>Processing Node 0 algo= PRICE_AND_CUT phase= PHASE_PRICE1 c= 0 p= 2 LB= 0.000 UB= 6.500 nodeLB= 0.000 gLB= 0.000 gUB=<br>
INF lpGap= 6.500 ipGap= INF time= 1.76<br>Processing Node 0 algo= PRICE_AND_CUT phase= PHASE_PRICE1 c= 0 p= 3 LB= 1.400 UB= 4.800 nodeLB= 1.400 gLB= 1.400 gUB=<br> INF lpGap= 2.429 ipGap= INF time= 1.85<br>
Processing Node 0 algo= PRICE_AND_CUT phase= PHASE_PRICE1 c= 0 p= 4 LB= 4.000 UB= 4.000 nodeLB= 4.000 gLB= 4.000 gUB=<br> INF lpGap= 0.000 ipGap= INF time= 1.90<br><br>Alps0202I Problem is infeasible. 1 nodes processed, 0 nodes left<br>
Alps0264I No solution found<br>Alps0265I Number of nodes fully processed: 1<br>Alps0266I Number of nodes partially processed: 0<br>Alps0267I Number of nodes branched: 0<br>Alps0268I Number of nodes pruned before processing: 0<br>
Alps0270I Number of nodes left: 0<br>Alps0272I Tree depth: 0<br>Alps0274I Search CPU time: 0.40 seconds<br>Alps0278I Search wall-clock time: 0.40 seconds<br><br>========== DECOMP Statistics [BEGIN]: =========<br>
Total Decomp = 0.34 100.00 1 0.34<br>Total Solve Relax = 0.31 90.00 25 0.08<br>Total Solve Relax App = 0.00 0.00 25 0.00<br>Total Solution Update = 0.00 1.18 4 0.00<br>
Total Generate Cuts = 0.00 0.00 0 0.00<br>Total Generate Vars = 0.03 9.12 4 0.02<br>Total Compress Cols = 0.00 0.00 0 0.00<br>========== DECOMP Statistics [END ]: =========<br>
Status= 5 BestLB= -INF BestUB= INF Nodes= 1 SetupCPU= 1.50 SolveCPU= 0.52 TotalCPU= 2.03 SetupReal= 1.50 SolveReal= 0.52 TotalReal=<br> 2.03<br><br><br><br>but branch and cut ends to following log:<br><br>
....<br>Alps0208I Search completed.<br>Alps0261I Best solution found had quality -16 and was found at depth 1<br>Alps0265I Number of nodes fully processed: 3<br>Alps0266I Number of nodes partially processed: 0<br>
Alps0267I Number of nodes branched: 1<br>Alps0268I Number of nodes pruned before processing: 0<br>Alps0270I Number of nodes left: 0<br>Alps0272I Tree depth: 1<br>Alps0274I Search CPU time: 0.44 seconds<br>
Alps0278I Search wall-clock time: 0.44 seconds<br><br>========== DECOMP Statistics [BEGIN]: =========<br>Total Decomp = 0.39 100.00 3 0.29<br>Total Solve Relax = 0.00 0.00 0 0.00<br>
Total Solve Relax App = 0.00 0.00 0 0.00<br>Total Solution Update = 0.01 1.27 7 0.00<br>Total Generate Cuts = 0.12 29.52 5 0.02<br>Total Generate Vars = 0.00 0.00 0 0.00<br>
Total Compress Cols = 0.00 0.00 0 0.00<br>========== DECOMP Statistics [END ]: =========<br>Status= 0 BestLB= -16.00000 BestUB= -16.00000 Nodes= 3 SetupCPU= 1.06 SolveCPU= 0.56 TotalCPU= 1.62 SetupReal= 1.06 SolveReal= 0.56 TotalReal=<br>
1.62<br>Optimal Solution<br><br><br><br>how to interpret this? the optimal solution of doCut is correct.<br>I have difficulties to understand what goes wrong that makes the problem infeasible.<br><br>I appreciate any comment.<br>
<br>regards,<br>Shahin<br><br><br><br><br><br><br><br><br>