[Coin-discuss] Wrong number of rows

[Matthew Saltzman]

Jesper-

What version of XPRESS are you using?  Can you send me (off-list) a small
example problem and code that shows the issue?

Thanks.

On Wed, 28 Jan 2004, Jesper Hansen wrote:

> 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!
>
>

-- 
		Matthew Saltzman

Clemson University Math Sciences
mjs AT clemson DOT edu
http://www.math.clemson.edu/~mjs