[Cbc] Assertion `feasible' failed in small MIP

[Haroldo Gambini Santos]

Hi Forrest,

If you commit this change I can test if the behavior is fixed.


On 13-09-2014 05:04, John Forrest wrote:
> Haroldo,
>
> I am unable to reproduce - what exactly were your configure options?
>
> However I think I can see the problem.  There seem to be lots of 
> solutions at  -13855499.9997 and they are checked several times before 
> being rejected as no better than best so far.  Some of these solutions 
> come while trying a more primitive (but faster) branch and bound.  
> There is code that sets fathomDone to true if it thinks a solution is 
> better than best so far when obtained in that way - it used 0.1 better 
> as a test.  The assert is
>
>                 if (fathomDone)
>                     assert (feasible);
>
> Anyway it looks as if due to accuracy problems fathomDone got set true 
> and then a double check resolve decided it was actually worse than cutoff.
>
> fathomDone was only used for that assert - so not used in optimized 
> mode.  My lazy inclination is just to take out fathomDone (and assert) 
> - it was only in when that bit of code was new (a few years ago).
>
> John
>
>
>
> On 13/09/14 04:17, Haroldo Gambini Santos wrote:
>> Hi,
>>
>> I've got this small MIP:
>> http://www.decom.ufop.br/haroldo/files/layer2.mps
>>
>> Where CBC (current trunk, revision 2070) fails:
>> Cbc0038I Full problem 185 rows 111 columns, reduced to 77 rows 38 columns
>> *cbc: CbcModel.cpp:16111: int CbcModel::doOneNode(CbcModel*, 
>> CbcNode*&, CbcNode*&): Assertion `feasible' failed.*
>

-- 
==================================================
Haroldo Gambini Santos
D.Sc, Computer Science
Universidade Federal de Ouro Preto
http://www.decom.ufop.br/haroldo/

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://list.coin-or.org/pipermail/cbc/attachments/20140913/5c0a96b2/attachment.html>