[Osi-tickets] [COIN-OR Open Solver Interface] #84: getBasics without enableSimplexInterface

COIN-OR Open Solver Interface coin-trac at coin-or.org
Wed Sep 9 16:26:18 EDT 2009

#84: getBasics without enableSimplexInterface
 Reporter:  mgalati  |       Owner:  mjs    
     Type:  defect   |      Status:  new    
 Priority:  major    |   Milestone:         
Component:  OsiClp   |     Version:  0.100.0
 Keywords:           |  
 Hi - it seems that enableSimplexInterface must be set to use getBasics().
 The user should get some kind of error message telling them to do this in
 order to use getBasics.

 Alternatively, Laci told me that one can also get the basis header from
 getWarmStart - which does not need enableSimplexInterface. This worked for
 me. Can we change the OsiClp API so that getBasics does this for the user
 when enableSimplexInterface is not set? i.e., getWarmStart and then get
 header information from that?


     I am using OsiClp in a normal manner. Load problem, solve, add some
 columns, resolve, etc... Periodically, I want to get the basis header. I
 get the following assertion failure. Do I need to do something special to
 get basics? There is no error message, just a failed assertion.

     decomp_gap: ../../../../Osi/src/OsiClp/OsiClpSolverInterface.cpp:6071:
 virtual void OsiClpSolverInterface::getBasics(int*) const: Assertion
 `modelPtr_->pivotVariable()' failed.

Ticket URL: <https://projects.coin-or.org/Osi/ticket/84>
COIN-OR Open Solver Interface <http://projects.coin-or.org/Osi>
An API for a variety of LP and MIP solvers (and more).

More information about the Osi-tickets mailing list