[Cbc] More problem with re-solving a model

[Goossens Jan-Willem]

John,

Thanks for your reply. This is not an urgent issue. The save/reset approach works fine for now.
Also, after giving it some thought, I can see justification to keep an original copy of (quite a big part of) the data.

Mostly, though, I was surprised to have to manually do the save/reset mechanism.
Is (should) this kind of behavior part of the description of what any OSI implementation should do?

Regards,

Jan-Willem


From: cbc-bounces at list.coin-or.org [mailto:cbc-bounces at list.coin-or.org] On Behalf Of John J Forrest
Sent: Tuesday, April 07, 2009 17:12
Cc: cbc at list.coin-or.org
Subject: Re: [Cbc] More problem with re-solving a model


Jan-Willem,

I am a bit unavailable at present but can try and improve things for you by early next week. If you send me some pseudo code and details of how desperate you are to save memory, I can think what would be useful for you and others.

John Forrest

[cid:image001.gif at 01C9BCEE.BBF51810]Goossens Jan-Willem ---04/06/2009 09:48:03 AM---Hi,

From:


Goossens Jan-Willem <Jan-Willem.Goossens at nc3a.nato.int>


To:


"cbc at list.coin-or.org" <cbc at list.coin-or.org>


Date:


04/06/2009 09:48 AM


Subject:


[Cbc] More problem with re-solving a model

________________________________



Hi,

I’m trying to solve a problem with CBC, add a constraint that cuts off the last integer solution, and solve again (it’s a covering problem, and I’m trying to find all covers).

I kept hitting the problem that after the first solve, the model was littered with extra bounds, I guess from the B&B process (right?)
Fortunately, I read http://list.coin-or.org/pipermail/cbc/2008-February/000098.html
“use saveReferenceSolver() initially and then use resetToReferenceSolver() to reset bounds and everything”

So is this Reference Solver instance a full copy of the problem? I’m having problems fitting the problem into memory as it is, let alone keeping two around..

Thanks,

Jan-Willem_______________________________________________
Cbc mailing list
Cbc at list.coin-or.org
http://list.coin-or.org/mailman/listinfo/cbc

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