Re: [Help-glpk] problem with glp_ios_heur_sol

[Giorgio Sartor]

Well, I don't know what you mean exactly but setting parm.presolve = ON is never NECESSARY! (It is necessary only if you don't want to use glp_simplex before glp_intopt). If you don't use it, my suggestion is to use glp_simplex before glp_intopt and disable parm.presolve. In this case, if the integer solution found is incorrect means that the solution you pass is incorrect.

2013/8/6 Le Dinh Danh <address@hidden>

Hi G.S,

It is neccesary to set parm.presolve=ON before solving MIP. In fact, I've tried with parm.presolve=OFF but the results are always 0. Anyway, thank you.

On Mon, Aug 5, 2013 at 5:34 PM, Giorgio Sartor <address@hidden> wrote:

Ok. Just try parm.presolve=OFF and let me know if then works.

- G. S. -

Il giorno 05/ago/2013, alle ore 16:51, Le Dinh Danh <address@hidden> ha scritto:

Hi Giorgio Sartor,

On Mon, Aug 5, 2013 at 4:14 PM, Giorgio Sartor <address@hidden> wrote:

Is glp_iocp.presolve activated?

Yes, I have already set parm.presolve = ON.

A common cause of incorrect solutions is that your solution is correct for the original problem but not correct for the current problem (which could have been modified by GLPK during the solving process).

Stupid question: does your solution start from position 1 of the array?

Yes, of course. 

- G. S. -

Il giorno 05/ago/2013, alle ore 14:58, Le Dinh Danh <address@hidden> ha scritto:

With "the result is still incorrect" I mean after calling the callback function, the solver find the solution but it is not correct one. I don't know why. If I don't call the cacllback, the solve provide a good solution. I can check it manually.

On Mon, Aug 5, 2013 at 1:19 PM, Giorgio Sartor <address@hidden> wrote:

What do you mean with "the result is still incorrect"?


- G. S. -

Il giorno 05/ago/2013, alle ore 12:57, Le Dinh Danh <address@hidden> ha scritto:

> the result is still incorrect.

--

Le Dinh Danh

LIRMM, 161 rue Ada, 34095 Montpellier Cedex 5

Email: address@hidden; address@hidden               

Tel: (+84) 912.449.666; (+33) 6.52.98.59.66 

--

Le Dinh Danh

LIRMM, 161 rue Ada, 34095 Montpellier Cedex 5

Email: address@hidden; address@hidden               

Tel: (+84) 912.449.666; (+33) 6.52.98.59.66 

--

Le Dinh Danh

LIRMM, 161 rue Ada, 34095 Montpellier Cedex 5

Email: address@hidden; address@hidden               

Tel: (+84) 912.449.666; (+33) 6.52.98.59.66