[Fwd: Bus error for MIP solver / Simplex solver]

[Andrew Makhorin]

-------- Forwarded Message --------
From: Tony Khosravi <tony.khosravid@...>
To: bug-glpk@...
Subject: Bus error for MIP solver / Simplex solver
Date: Tue, 17 Apr 2012 16:27:47 +0200

Hi,

I am trying to use the GLPK API. Therefore, I tried to implement a
simple call to the glp_intopt. However, I face a Bus error problem. I
provided some parameters to use the presolver, and it seems to crash
after the call of the simplex solver.
The code I used is totally based on the second example of the
documentation about Routines for processing MathProg models.
The only thing i do more is the following:


    glp_init_iocp(parm);
    parm->presolve = GLP_ON;
    parm->binarize = GLP_ON;

and then

    glp_intopt(mip, parm);

Then I don't call the glp_simplex method. The files I used are the ones
provided in the examples, sudoku.dat and sudoku.mod.

Here is the output generated:

Reading model section from sudoku.mod...
sudoku.mod:69: warning: data section ignored
69 lines were read
Reading data section from sudoku.dat...
16 lines were read
Generating fa...
Generating fb...
Generating fc...
Generating fd...
Generating fe...
Model has been successfully generated
GLPK Integer Optimizer, v4.47
504 rows, 729 columns, 3096 non-zeros
729 integer variables, all of which are binary
Preprocessing...
204 rows, 179 columns, 716 non-zeros
179 integer variables, all of which are binary
Scaling...
 A: min|aij| =  1.000e+00  max|aij| =  1.000e+00  ratio =  1.000e+00
Problem data seem to be well scaled
Constructing initial basis...
Size of triangular part = 132
Solving LP relaxation...
GLPK Simplex Optimizer, v4.47
204 rows, 179 columns, 716 non-zeros
Bus error

Using the stand alone solver is not a problem though, I can use it to
solve without any problems.

Moreover, I tried the code directly provided by the documentation
(example 2 still) and the solution is actually not the same as the stand
alone solver. I assumed because there is not use of the presolver in the
example.

I thought it might be a problem of 64-bits architecture, since I am
running on LinuxMint 64 bit, and I try to compile with the -m64 option
(using gcc), but it didn't solve the problem.

Best regards,

--
Tony Khosravi Dehkourdi

MSc. Student - Computer Systems
Linköping University
Elève ingénieur -- Génie Informatique, Systèmes et Réseaux
d'Informations (GI06)
Université de Technologie de Compiègne
Tel:[phone]


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