[Coin-discuss] Wrong number of rows

[Jesper Hansen]

Hi COIN

I'm trying to solve an IP problem with XPRESS using OSI. However when 
calling branchAndBound the number of rows increase. Here is the code snip 
and the output:

    logs->out() << "Before B&B. Number of rows: " << solver->getNumRows() 
<< std::endl;
    solver->branchAndBound();
    logs->out() << "After B&B. Number of rows: " << solver->getNumRows() 
<< std::endl;


Before B&B. Number of rows: 149
After B&B. Number of rows: 162

The MPS dump looks fine before the branchAndBound call, but afterwards... 
:-( 

For instance column 310 was originally:    

C310      __OBJ___  -9993547.000   R98           1.000000
C310      R47           1.000000

and after branchAndBound it is:
C310      __OBJ___  -9993547.000   R47           1.000000
C310      R98           1.000000   R154          4.000000
 
Any ideas to avoid this?

Note that solving with CLP and SBB works just fine!

-- 
Jesper Hansen, mailto:Jesper at carmenconsulting.com
Carmen Consulting, Købmagergade 53, Copenhagen K, Denmark 
Tel.: +45 33 17 91 92    Mobil: +45 61 33 29 69
http://www.carmenconsulting.com