[Cbc] failure in small IP
Matthew Galati
magh at lehigh.edu
Thu Sep 10 12:38:33 EDT 2009
Thanks John. When you say "different" do you mean actually different or just
the way they are stored?
I.e., if I want to know which variables are basic after a solve - and I
getWarmStart and check the structural status - will that information match
what getBasics would return?
Matt,
>
> Thanks.
>
> As to getBasics - the two sets of information are different - but I will
> modify to point out options to user.
>
> John
>
> [image: Inactive hide details for Matthew Galati ---09/10/2009 12:37:54
> AM---Here is a fix. It was just missing an initialization in Cb]Matthew
> Galati ---09/10/2009 12:37:54 AM---Here is a fix. It was just missing an
> initialization in CbcRounding constructor. [magala at orclus71 sr
>
>
> From:
> Matthew Galati <Matthew.Galati at sas.com>
> To:
>
> Matthew Galati <magh at lehigh.edu>
> Cc:
> "cbc at list.coin-or.org" <cbc at list.coin-or.org>
> Date:
> 09/10/2009 12:37 AM
>
> Subject:
> Re: [Cbc] failure in small IP
> Sent by:
> cbc-bounces at list.coin-or.org
> ------------------------------
>
>
>
> Here is a fix. It was just missing an initialization in CbcRounding
> constructor.
>
>
>
> [magala at orclus71 src]$ svn diff CbcHeuristic.cpp
> Index: CbcHeuristic.cpp
> ===================================================================
> --- CbcHeuristic.cpp (revision 1223)
> +++ CbcHeuristic.cpp (working copy)
> @@ -1538,6 +1538,9 @@
> {
> // Get a copy of original matrix (and by row for rounding);
> assert(model.solver());
> + down_=NULL;
> + up_=NULL;
> + equal_=NULL;
> if (model.solver()->getNumRows()) {
> matrix_ = *model.solver()->getMatrixByCol();
> matrixByRow_ = *model.solver()->getMatrixByRow();
>
>
>
> *From:* Matthew Galati [mailto:magh at lehigh.edu <magh at lehigh.edu>] *
> Sent:* Thursday, September 10, 2009 12:19 AM*
> To:* Matthew Galati*
> Cc:* cbc at list.coin-or.org*
> Subject:* Re: [Cbc] failure in small IP
>
> The run with cbc executable that does not fail was using a May 2009 version
> of code.
>
> Using the current trunk it fails (same as when using CbcMain1):
>
> [magala at orclus71 src]$ ./cbc ~/subProb.n0.c0.p1.b0.lp
>
> Coin Cbc and Clp Solver version 1.2trunk, build Sep 10 2009
>
> command line - ./cbc /users/magala/subProb.n0.c0.p1.b0.lp (default strategy
> 1)
>
> Continuous objective value is 46.6667 - 0.00 seconds
>
> Cgl0003I 20 fixed, 0 tightened bounds, 0 strengthened rows, 0 substitutions
>
> Cgl0003I 5 fixed, 0 tightened bounds, 0 strengthened rows, 8 substitutions
>
> Cgl0003I 0 fixed, 0 tightened bounds, 0 strengthened rows, 8 substitutions
>
> Cgl0004I processed model has 0 rows, 0 columns (0 integer) and 0 elements
>
> Segmentation fault
>
>
> The following small IP fails using the CbcMain1 interface. It is a unique
> case, because all rows and cols are removed by presolver.
>
> *http://coral.ie.lehigh.edu/~magh/tmp/subProb.n0.c0.p1.b0.lp*<http://coral.ie.lehigh.edu/%7Emagh/tmp/subProb.n0.c0.p1.b0.lp>
>
> *https://projects.coin-or.org/Cbc/ticket/79*<https://projects.coin-or.org/Cbc/ticket/79>
>
> CbcModel cbc(*subprobSI);
>
> CbcMain0(cbc);
>
> const char * argv[] = {"cbc","-solve","-quit"};
>
> CbcMain1(3, argv, cbc);
>
> Coin Cbc and Clp Solver version 1.2trunk, build Sep 9 2009
>
> command line - cbc -solve -quit (default strategy 1)
>
> Continuous objective value is 46.6667 - 0.00 seconds
>
> Cgl0003I 20 fixed, 0 tightened bounds, 0 strengthened rows, 0 substitutions
>
> Cgl0003I 5 fixed, 0 tightened bounds, 0 strengthened rows, 8 substitutions
>
> Cgl0003I 0 fixed, 0 tightened bounds, 0 strengthened rows, 8 substitutions
>
> Cgl0004I processed model has 0 rows, 0 columns (0 integer) and 0 elements
>
> gdb gives:
>
> Program received signal SIGSEGV, Segmentation fault.
>
> 0x0000003ffa871f6b in free () from /lib64/libc.so.6
>
> (gdb) where
>
> #0 0x0000003ffa871f6b in free () from /lib64/libc.so.6
>
> #1 0x000000000057bc41 in ~CbcRounding (this=0x7fffec90c080)
>
> at ../../../Cbc/src/CbcHeuristic.cpp:1552
>
> #2 0x00000000004ae837 in doHeuristics (model=0x1d1f3e00, type=1)
>
> at ../../../Cbc/src/CbcSolver.cpp:3479
>
> #3 0x00000000004c7776 in CbcMain1 (argc=3, argv=0x7fffec9150c0,
>
> model=@0x7fffec914bb0, callBack=0x4a734c <dummyCallBack>)
>
> at ../../../Cbc/src/CbcSolver.cpp:6680
>
> #4 0x00000000004db968 in CbcMain1 (argc=3, argv=0x7fffec9150c0,
>
> model=@0x7fffec914bb0) at ../../../Cbc/src/CbcSolver.cpp:3099
>
> Note, if I run it from the command line using cbc executable, the error
> does not occur.
>
> [magala at orclus71 MMKP]$ ~/COIN/coin-Cbc/build-g/bin/cbc
> subProb.n0.c0.p1.b0.lp
>
> Coin Cbc and Clp Solver version 1.2trunk, build May 27 2009
>
> command line - /users/magala/COIN/coin-Cbc/build-g/bin/cbc
> subProb.n0.c0.p1.b0.lp (default strategy 1)
>
> Continuous objective value is 46.6667 - 0.00 seconds
>
> Cgl0003I 20 fixed, 0 tightened bounds, 0 strengthened rows, 0 substitutions
>
> Cgl0003I 5 fixed, 0 tightened bounds, 0 strengthened rows, 8 substitutions
>
> Cgl0003I 0 fixed, 0 tightened bounds, 0 strengthened rows, 8 substitutions
>
> 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 46.6667 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 46.66667 after 0 nodes and 0 iterations - took
> 0.00 seconds (total time 0.01)
>
> Total time 0.01
>
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