Opened 11 years ago
Closed 11 years ago
#69 closed defect (fixed)
CBC 2.2.2 returns sub-optimal solution
Reported by: | knark | Owned by: | somebody |
---|---|---|---|
Priority: | major | Component: | component1 |
Version: | 2.0 | Keywords: | |
Cc: |
Description
CBC 2.2.2 returns an objective value of -960 for the attached small MIP model while the optimal objective value is -1160. I used MS V8 on Windows.
Coin Cbc and Clp Solver version 2.20.00, build Feb 25 2009 command line - cbcsolve cbc00001.mps -solve At line 1 NAME BLANK At line 2 ROWS At line 5 COLUMNS At line 17 RHS At line 19 BOUNDS At line 31 ENDATA Problem BLANK has 1 rows, 11 columns and 11 elements Coin0008I BLANK read with 0 errors Continuous objective value is -1194.03 - 0.00 seconds Optimal - objective value -1194.03 Cgl0004I processed model has 0 rows, 0 columns (0 integer) and 0 elements Cbc3007W No integer variables - nothing to do Cuts at root node changed objective from -960 to -1.79769e+308 Probing was tried 0 times and created 0 cuts of which 0 were active after adding rounds of cuts (0.000 seconds) Gomory was tried 0 times and created 0 cuts of which 0 were active after adding rounds of cuts (0.000 seconds) Knapsack was tried 0 times and created 0 cuts of which 0 were active after adding rounds of cuts (0.000 seconds) Clique was tried 0 times and created 0 cuts of which 0 were active after adding rounds of cuts (0.000 seconds) MixedIntegerRounding2 was tried 0 times and created 0 cuts of which 0 were active after adding rounds of cuts (0.000 seconds) FlowCover was tried 0 times and created 0 cuts of which 0 were active after adding rounds of cuts (0.000 seconds) TwoMirCuts was tried 0 times and created 0 cuts of which 0 were active after adding rounds of cuts (0.000 seconds) Result - Finished objective -960 after 0 nodes and 0 iterations - took 0.00 seconds (total time 0.00) Total time 0.00
The CBC version at COIN-OR returns the correct value of -1160:
Coin Cbc and Clp Solver version 1.01.00, build Aug 18 2006 command line - /home/neos/neos-bin/cbc cbc.mps At line 1 NAME BLANK At line 2 ROWS At line 5 COLUMNS At line 17 RHS At line 19 BOUNDS At line 31 ENDATA Problem BLANK has 1 rows, 11 columns and 11 elements Model was imported from ./cbc.mps in 0 seconds Optimal - objective value -1194.03 Cgl0004I processed model has 1 rows, 11 columns (11 integer) and 11 elements processed model has 1 rows, 11 columns and 11 elements Optimal - objective value -1184 11 integer variables - solution found Cbc0012I Integer solution of -1160 found by heuristic after 0 iterations and 0 nodes (0.01 seconds)
Attachments (1)
Change History (3)
Changed 11 years ago by knark
comment:1 in reply to: ↑ description Changed 11 years ago by knark
comment:2 Changed 11 years ago by forrest
- Resolution set to fixed
- Status changed from new to closed
trunk seems okay - should be moving to stable
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Ups, I meant NEOS.