[Coin-discuss] no integers in writeMps?
John J Forrest
jjforre at us.ibm.com
Fri Feb 4 09:13:41 EST 2005
Brady,
CoinMpsIO uses UI and BV in bounds section which I think is more elegant
and is accepted by most solvers.
John
Brady Hunsaker <hunsaker at engr.pitt.edu>
Sent by: coin-discuss-bounces at list.coin-or.org
02/03/2005 06:13 PM
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Re: [Coin-discuss] no integers in writeMps?
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/
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