[Coin-lpsolver] abandoned termcode with bad bounds

Ashutosh Mahajan asm4 at Lehigh.EDU
Mon Oct 16 16:48:59 EDT 2006


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

hi,
  Im using OsiClp. If my problem has bad bounds for a variable (lb[var] >
  ub[var]), initialSolve returns isAbandoned rather than the expected
  primal-infeasible.

  here is an example to reproduce the error:

  #include "OsiClpSolverInterface.hpp"
  #include <stdlib.h>

  int main()
  {
	  OsiClpSolverInterface *si = new OsiClpSolverInterface();
	  si->readMps("/home/asm4/miplib/p0033.mps");
	  // Set bad bounds for variable 1
	  si->setColLower(1,1);
	  si->setColUpper(1,0);
	  si->initialSolve();
	  if (si->isAbandoned()) {
	      printf("**** Abandoned\n");
	  }
  }

output of the program is:
Clp0006I 0  Obj 171 Primal inf 17.73 (9)
Clp0006I 17  Obj 2520.57
Clp0000I Optimal - objective value 2520.57
Coin0511I After Postsolve, objective 2520.57, infeasibilities - dual 0 (0),
primal 1 (1)
Coin0512I Presolved model was optimal, full model needs cleaning up
Clp6002E 1 bad bound pairs or bad objectives were found - first at C1
Clp0004I Stopped due to errors - objective value 2520.57
Clp0032I Errors objective 2520.571739 - 17 iterations time 0.002, Presolve
- -0.00
**** Abandoned

Is this the expected behaviour? or a bug?
im using the code from the svn-trunk.

thanks in advance.
- --
regards
Ashutosh Mahajan
http://www.lehigh.edu/~asm4

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.5 (GNU/Linux)

iD8DBQFFM/A7VsGrdJ19wHsRAnniAJ42XqNSSXkx27YScq8cjJ6448cyHACfVvYp
CVKxQ7xnyZBn7w7lD7XmDeM=
=LH+G
-----END PGP SIGNATURE-----



More information about the Clp mailing list