[Clp] CLP bug?

[John J Forrest]

You are correct - there was a bug when checking empty problems.

By the way - are you sure you meant to have an empty column 0?.

John Forrest


                                                                                                                           
  From:       "Mustafa Kilinc" <mrkilinc at gmail.com>                                                                        
                                                                                                                           
  To:         clp at list.coin-or.org                                                                                         
                                                                                                                           
  Date:       06/18/2008 11:05 AM                                                                                          
                                                                                                                           
  Subject:    [Clp] CLP bug?                                                                                               
                                                                                                                           





I am trying to solve the following model with osiclp;

    Objective in sparse format:
      [    1 ,         -1]  [    2 ,          0]
    Constraints in sparse format:
      row     1:          1 <=    [    1 ,          0]   [    2 ,
0] <=          1
    Simple bounds (lower, upper):
      var     1: (       -10 ,         10)
      var     2: (       -10 ,         10)

When I call si->initialSolve(); it prints out:

Clp0024I Matrix will be packed to eliminate 2 small elements
Coin0507I Presolve determined that the problem was infeasible with
tolerance of 1e-08
Clp3003W Analysis indicates model infeasible or unbounded
Clp0000I Optimal - objective value -10
Clp0032I Optimal objective -10 - 0 iterations time 0.002

And si->isProvenOptimal() returns true.

Presolve determines the problem is infeasible but Clp says it is optimal.

Mustafa_______________________________________________
Clp mailing list
Clp at list.coin-or.org
http://list.coin-or.org/mailman/listinfo/clp