[Cbc-tickets] [COIN-OR Branch-and-Cut MIP Solver] #151: quadratic objective with cbc

[COIN-OR Branch-and-Cut MIP Solver]

#151: quadratic objective with cbc
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Reporter:  godsend  |      Owner:  tkr
    Type:  defect   |     Status:  new
Priority:  major    |  Component:  Cbc
 Version:  2.8      |   Keywords:
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 Hello,

 I read that cbc can solve quadratic problem or I didn't understand.

 At the page http://www.coin-or.org/Cbc/cbcuserguide.html, point 7, topic
 Quadratic MIP, it's written "it is possible to do quadratic MIP with CBC".
 furthermore, Cbc provide some quadratic problem exemples : quad.mps and
 quad2.mps with the keyword "QUADOBJ".

 So, if I try to solve quad.mps I have some problems.

 First case (result file : firstcase.txt) :
 I open cbc with shell and I import quad.mps
 --------------------------------------------------
 Coin:import quad.mps
 ...
 Coin:solve
 ...
 Result - Optimal solution found

 Objective value:                27797.14684147
 Enumerated nodes:               30530
 Total iterations:               3410826
 Time (CPU seconds):             208.77
 Time (Wallclock seconds):       210.57
 --------------------------------------------------

 But if I want to print the result I have a segment fault :
 --------------------------------------------------
 Coin:solution solution.txt
 Erreur de segmentation (core dumped)
 --------------------------------------------------

 Second case (result file : secondcase.txt) :
 With a command line in the shell, I have no solution :
 --------------------------------------------------
 cbc quad.mps -solution stdout


 Welcome to the CBC MILP Solver
 Version: 2.8
 Build Date: May  7 2014
 Revision Number: 2031

 command line - cbc quad.mps -solution stdout (default strategy 1)
 At line 1 NAME
 At line 2 ROWS
 At line 299 COLUMNS
 At line 778 RHS
 At line 878 BOUNDS
 At line 985 QUADOBJ
 Problem no_name has 295 rows, 260 columns and 869 elements
 Coin0008I no_name read with 0 errors
 At line 1000 ENDATA
 Status unknown - objective value 0.00000000
 Total time (CPU seconds):       0.00   (Wallclock seconds):       0.00
 --------------------------------------------------

 But if and don't ask the solution it seems to work but impossible to know
 the details of the solution. I added that Gurobi find different objective
 value (file : gurobi.txt) :
 --------------------------------------------------
 cbc quad.mps


 Result - Optimal solution found

 Objective value:                27797.14684147
 Enumerated nodes:               30530
 Total iterations:               3410826
 Time (CPU seconds):             208.56
 Time (Wallclock seconds):       211.71

 Total time (CPU seconds):       208.56   (Wallclock seconds):       211.71
 --------------------------------------------------


 So, is it a bug ? Cbc can solve quadratic model ? Do you have any ideas ?

 Thanks for your help and for your work. You provide very good products.

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Ticket URL: <https://projects.coin-or.org/Cbc/ticket/151>
COIN-OR Branch-and-Cut MIP Solver <http://projects.coin-or.org/Cbc>
An LP-based branch-and-cut MIP solver.