[Help-glpk] [Fwd: Conflict graph is too big]

[Andrew Makhorin]

-------- Forwarded Message --------
From: Isa . <address@hidden>
To: address@hidden
Subject: Conflict graph is too big
Date: Mon, 9 May 2011 11:31:45 +0200

Good morning,
 
We are 3 students experiencing some problems with GLPK. 
When we compile, the system says the following:
 
GLPSOL: GLPK LP/MIP Solver, v4.45
Parameter(s) specified in the command line:
--cover --clique --gomory --mir -m Production de verres.mod
Reading model section from Production de verres.mod...
Reading data section from Production de verres.mod...
103 lines were read
Generating cout...
Generating equilibre_de_stock1...
Generating equilibre_de_stock2...
Generating stock_final...
Generating contrainte_physique...
Generating contrainte_technique...
Generating contrainte_spaciale...
Generating contrainte_de_non_negativite_production...
Generating contrainte_de_non_negativite_stock...
Model has been successfully generated
GLPK Integer Optimizer, v4.45
259 rows, 144 columns, 720 non-zeros
144 integer variables, none of which are binary
Preprocessing...
108 rows, 144 columns, 426 non-zeros
144 integer variables, none of which are binary
Scaling...
A: min|aij| = 1.000e+000  max|aij| = 1.100e+001  ratio = 1.100e+001
GM: min|aij| = 5.373e-001  max|aij| = 1.861e+000  ratio = 3.464e+000
EQ: min|aij| = 2.887e-001  max|aij| = 1.000e+000  ratio = 3.464e+000
2N: min|aij| = 2.500e-001  max|aij| = 1.500e+000  ratio = 6.000e+000
Constructing initial basis...
Size of triangular part = 108
Solving LP relaxation...
GLPK Simplex Optimizer, v4.45
108 rows, 144 columns, 426 non-zeros
      0: obj = -1.721240000e+005  infeas = 9.429e+003 (0)
*    90: obj =  1.990017261e+005  infeas = 2.188e-016 (0)
*   134: obj =  1.843621667e+005  infeas = 0.000e+000 (0)
OPTIMAL SOLUTION FOUND
Integer optimization begins...
Gomory's cuts enabled
MIR cuts enabled
Cover cuts enabled
Clique cuts enabled
Creating the conflict graph...
The conflict graph is either empty or too big
+   134: mip =     not found yet >=              -inf        (1; 0)
 
After this line, it keeps on searching infinitely for an optimal
solution. 
How come it doesn’t find it? And what does it mean that the conflict
graph is either empty or too big?
Our .mod file is attached to this email. 
 
Kind regards,
 
Isabelle
Maïté
Virginie

Production de verres.mod
Description: Binary data