[Cbc] Assertion failure in trunk and devel branch

Thu Jun 21 07:02:58 EDT 2007

This occurred in trunk because some code in Cgl/trunk had been "improved".
branches/devel allowed for this but trunk did not.

Should be Ok in trunk now.

John Forrest

             Esben Mose Hansen                                             
             <esben at ange.dk>                                               
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             coin-or.org                                                cc 

                                                                   Subject 
             06/20/07 10:19 AM         [Cbc] Assertion failure in trunk    
                                       and devel branch                    

Hi,

I can't seem to login to trac, it behaves very strangely. So:

Provide I compile coin without -DNDEBUG, I can consistently trip an
assertion
like this:

wget http://sirius.ange.dk/public/slot_cs_8_1_10.mps
cbc slot_cs_8_1_10.mps solve solve

The double solve is no accident, it only happens on the second solve ---
though I suspect that solving any problem first will trigger the assertion.

This is the output from cbc:

esben at mosegris:~/orion-trunk/solver$ cbc slot_cs_8_1_10.mps solve solve
Coin Cbc and Clp Solver version 1.01.00, build Jun 20 2007
command line - cbc slot_cs_8_1_10.mps solve solve
At line 1 NAME          BLANK
At line 2 ROWS
At line 44 COLUMNS
At line 866 RHS
At line 881 BOUNDS
At line 1035 ENDATA
Problem BLANK has 40 rows, 158 columns and 1416 elements
Model was imported from ./slot_cs_8_1_10.mps in 0.008001 seconds
Optimal - objective value 18.9836
Cgl0006I 17 SOS (153 members out of 153) with 204 overlaps - too much
overlap
or too many others
Cgl0003I 0 fixed, 3 tightened bounds, 0 strengthened rows, 0 substitutions
Cgl0004I processed model has 24 rows, 37 columns (34 integer) and 241
elements
processed model has 24 rows, 37 columns and 241 elements
Optimal - objective value 18.9836
34 integer variables and 3 variables could be made integer

pass   1: obj.    0.00000 --> up =     0 , down =     0 -- rand =    0 (
11)  - solution found
Cbc0012I Integer solution of 19.0971 found by heuristic after 0 iterations
and
0 nodes (0.01 seconds)
Cbc0012I Integer solution of 19.0373 found by heuristic after 5 iterations
and
0 nodes (0.02 seconds)
Cbc0031I 2 added rows had average density of 34
Cbc0013I At root node, 2 cuts changed objective from 18.9836 to 19.0373 in
3
passes
Cbc0014I Cut generator 0 (Probing) - 0 row cuts (0 active), 0 column cuts
in
0.008001 seconds - new frequency is -100
Cbc0014I Cut generator 1 (Gomory) - 2 row cuts (0 active), 0 column cuts
in -4.92634e-18 seconds - new frequency is -100
Cbc0014I Cut generator 2 (Knapsack) - 0 row cuts (0 active), 0 column cuts
in
0.004 seconds - new frequency is -100
Cbc0014I Cut generator 3 (Clique) - 0 row cuts (0 active), 0 column cuts
in -2.20229e-18 seconds - new frequency is -100
Cbc0014I Cut generator 4 (MixedIntegerRounding2) - 2 row cuts (0 active), 0

column cuts  in -8.66006e-18 seconds - new frequency is -100
Cbc0014I Cut generator 5 (FlowCover) - 0 row cuts (0 active), 0 column cuts

in -2.20229e-18 seconds - new frequency is -100
Cbc0014I Cut generator 6 (TwoMirCuts) - 7 row cuts (2 active), 0 column
cuts
in -8.66006e-18 seconds - new frequency is -100
Cbc0001I Search completed - best objective 19.0373, took 5 iterations and 0

nodes (0.03 seconds)
Cuts at root node changed objective from 18.9836 to 19.0373
Probing was tried 3 times and created 0 cuts of which 0 were active after
adding rounds of cuts ( 0.008001 seconds)
Gomory was tried 3 times and created 2 cuts of which 0 were active after
adding rounds of cuts ( -4.92634e-18 seconds)
Knapsack was tried 3 times and created 0 cuts of which 0 were active after
adding rounds of cuts ( 0.004 seconds)
Clique was tried 1 times and created 0 cuts of which 0 were active after
adding rounds of cuts ( -2.20229e-18 seconds)
MixedIntegerRounding2 was tried 3 times and created 2 cuts of which 0 were
active after adding rounds of cuts ( -8.66006e-18 seconds)
FlowCover was tried 1 times and created 0 cuts of which 0 were active after

adding rounds of cuts ( -2.20229e-18 seconds)
TwoMirCuts was tried 3 times and created 7 cuts of which 2 were active
after
adding rounds of cuts ( -8.66006e-18 seconds)
Result - Finished objective 19.0373 after 0 nodes and 5 iterations - took
0.096006 seconds
Optimal - objective value 18.9836
Cgl0006I 17 SOS (153 members out of 153) with 204 overlaps - too much
overlap
or too many others
Cgl0003I 0 fixed, 3 tightened bounds, 0 strengthened rows, 0 substitutions
Cgl0004I processed model has 24 rows, 37 columns (34 integer) and 241
elements
processed model has 24 rows, 37 columns and 241 elements
Optimal - objective value 18.9836
34 integer variables and 3 variables could be made integer
up =     0 , down =     0 -- rand =    2 (  14)  - solution found
Cbc0012I Integer solution of 19.0373 found by heuristic after 0 iterations
and
0 nodes (0.01 seconds)
cbc: ClpSimplexDual.cpp:1251: int ClpSimplexDual::whileIterating(double*&,
int): Assertion `fabs(dualOut_)<1.0e50' failed.
Aborted

--
regards, Esben

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