[SCIP] Disable knapsack cardinality cuts

[Stengel, Tobias]

Hello,

 

I'm using SCIP 7.0.3 for branch&cut with problem specific cut generation
(constraint handler adding rows). All separators are turned off by not
including the plugins.

 

I noticed that SCIP is spending a significant amount of time separating
knapsack cardinality cuts at the root node within the linear constraint
handler. Those cuts do not improve the dual bound for my problem.

As far as I can see this is caused by cons_linear.c line 15872ff because in
the root node the local bound equals the global bound and therefore 

 

SCIPisLE(scip, loclowerbound, maxbound);

 

return TRUE (with equality) no matter what value I set to
"constraints/linear/maxcardbounddist".

 

There are a few other parameter controlling the separation of linear
constraints, but I'm not sure what side effects it can have to disable
separation of linear constraints e.g. by setting 

constraints/linear/maxrounds = 0

 All my linear constraints are initial=TRUE and removable=FALSE.

 

As a workaround I can modify  cons_linear.c but it will probably hurt for
general MIP I'd like to solve with the same build...

 

Is there a clean way to disable knapsack cardinality cuts by setting
parameters?

 

 

 

With best regards,
Tobias Stengel

Siemens Digital Logistics GmbH
SL SDL TEC R&D SCS
Stumpfstr. 1
76131 Karlsruhe, Germany 
 <mailto:tobias.stengel at siemens-logistics.com>
mailto:tobias.stengel at siemens-logistics.com
 <http://www.siemens-digital-logistics.com>
www.siemens-digital-logistics.com

Management: Christopher Christian, Christian Schmidt
Registered office: Nachtweideweg 1-7, 67227 Frankenthal, Germany
Register Court: Ludwigshafen am Rhein, HRB 64386

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listserv.zib.de/pipermail/scip/attachments/20211029/a64ce695/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 14966 bytes
Desc: not available
URL: <http://listserv.zib.de/pipermail/scip/attachments/20211029/a64ce695/attachment.p7s>