[Coin-discuss] no integers in writeMps?

[Brady Hunsaker]

John J Forrest wrote:
> 
> Brady,
> 
> CoinMpsIO does write integer information if integrality array set.  This 
> is done automatically by OsiSolverInterface::writeMpsNative or can be 
> done by CoinMpsIO::copyInIntegerInformation.  How do you want it to work?
> 
> John
> 

Thanks for the quick reply, John.

I looked more carefully at the issue.  I'm using OsiCpx, and it turns 
out that OsiCpx uses CPLEX's routine for writing MPS files, which for 
some reason doesn't include the integrality information (perhaps it is 
relaxed?).  There is a comment in OsiCpxSolverInterface.cpp indicating 
that this is a known error.

An easy solution would be to change the code to use CoinMpsIO, based on 
your response.  I haven't tested this, but looking through the CoinMpsIO 
code, it doesn't look like this output includes integer information 
either.  At least, it doesn't appear to output "INTORG" and "INTEND" 
markers as I would expect.  Is it implemented in some other way?

Brady


> 
> *Brady Hunsaker <hunsaker at engr.pitt.edu>*
> Sent by: coin-discuss-bounces at list.coin-or.org
> 
> 02/02/2005 02:33 PM
> Please respond to
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> 	[Coin-discuss] no integers in writeMps?
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> 
> It appears that Coin writeMps does not indicate integer variables.  Is
> this correct?  Can we change that?
> 
> Brady
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-- 
Brady Hunsaker
Assistant Professor
Industrial Engineering
University of Pittsburgh
http://www.engr.pitt.edu/hunsaker/