[Osi-tickets] [COIN-OR Open Solver Interface] #94: OsiCpxSolverInterface's getWarmStart() returns incorrect row status

COIN-OR Open Solver Interface coin-trac at coin-or.org
Tue Sep 21 13:26:10 EDT 2010


#94: OsiCpxSolverInterface's getWarmStart() returns incorrect row status
------------------------+---------------------------------------------------
 Reporter:  ojasparekh  |       Owner:  mjs    
     Type:  defect      |      Status:  new    
 Priority:  major       |   Milestone:         
Component:  OsiCpx      |     Version:  0.100.2
 Keywords:              |  
------------------------+---------------------------------------------------
 Currently OsiCpxSolverInterface::getWarmStart matches it's returned Status
 value with the corresponding cplex value (e.g. CPX_AT_LOWER =>
 atLowerBound).  This is correct for ranged rows, but for others this
 correspondence is not quite correct:

 "[From cplex documentation: ] For rows other than ranged rows, the array
 element rstat[i] has the following meaning:
 CPX_AT_LOWER  0  associated slack/surplus/artificial variable non-basic at
 value 0.0
 CPX_BASIC  1  associated slack/surplus/artificial variable basic,"

 while the returned CoinWarmStartBasis::Status value has distinct statuses
 for non-basic variables depending on the type of non-ranged row.  The
 attached patch attempts to address this.

-- 
Ticket URL: <https://projects.coin-or.org/Osi/ticket/94>
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