[Cgl] knapsackcover seems to cut off optimal solution

[Robin Lougee-Heimer]

thanks - I see it.  can you try it with the latest version of stable? 

----------------------------------------------------------------------------------
Robin Lougee-Heimer, PhD
Program Manager, COIN-OR
IBM TJ Watson Research Center
1101 Kitchawan Road, Yorktown Heights, NY 10598
ph: 914-945-3032   fax: 914-945-3434 
robinlh at us.ibm.com
http://www.coin-or.org





Ashutosh Mahajan <asm4 at lehigh.edu> 
12/10/2009 08:38 PM

To
Robin Lougee-Heimer/Watson/IBM at IBMUS
cc
cgl at list.coin-or.org
Subject
Re: [Cgl] knapsackcover seems to cut off optimal solution






bug still persists. ticket opened. thanks.

ashutosh

On Thu, 10 Dec 2009, Robin Lougee-Heimer wrote:

>    Ashutosh:
> 
>    If this is still an issue, will you please report it in the Cgl bug
>    tracking factility?
> 
>    https://projects.coin-or.org/Cgl/report
> 
>    thanks,
>    Robin
> 
----------------------------------------------------------------------------------
>    Robin Lougee-Heimer, PhD
>    Program Manager, COIN-OR
>    IBM TJ Watson Research Center
>    1101 Kitchawan Road, Yorktown Heights, NY 10598
>    ph: 914-945-3032   fax: 914-945-3434
>    robinlh at us.ibm.com
>    http://www.coin-or.org
> 
>    Ashutosh Mahajan                   To cgl at list.coin-or.org
>    <asm4 at lehigh.edu>                  cc
>    Sent by:                      Subject [Cgl] knapsackcover seems to 
cut off
>    cgl-bounces at list.coin-or.org          optimal solution
> 
>    10/26/2009 03:18 PM
> 
>    one of the users of symphony provided an instance on which the
>    KnapsackCover
>    cuts off the optimal solution.
> 
>    the LP files and the code that reproduces the problem are located 
here:
> 
>    http://coral.ie.lehigh.edu/~asm4/tmp/knapsack/
> 
>    out1.lp is the original instance. out2.lp is the instance obtained 
after
>    adding CglKnapsackCover inequalities. solving out2.lp with cplex or 
cbc
>    gives
>    a solution value of 401, while out1.lp gives 397.
> 
>    This behaviour was seen with latest stable r792. i expect it in the
>    release
>    version as well (though i did not check). is this a bug, or something
>    wrong
>    with my construction?
> 
>    thanks.
>    --
>    regards
>    Ashutosh Mahajan
>    http://coral.ie.lehigh.edu/~asm4
> 
>    _______________________________________________
>    Cgl mailing list
>    Cgl at list.coin-or.org
>    http://list.coin-or.org/mailman/listinfo/cgl

--
regards
Ashutosh Mahajan
http://coral.ie.lehigh.edu/~asm4


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