Re: Math Program Inspector / MIP Search Tree Functionality

[Guido Diepen]

Hi Jan,

did you also set the project option 'Show branch and bound tree' to on before you did the solve? 

Guido Diepen

AIMMS Specialist

On Wednesday, May 15, 2013 4:44:51 PM UTC+2, Jan wrote:

Hi everyone,

I'm need to use the "MIP Search Tree Functionality" in the "Math Program Inspector". I've tried different settings, but with no success. I  am using CPLEX 12.5.

Does anybody has some experiece with the search tree viewer?

Thank you in advance
Jan

[Jan]

Hi Guido,

yes I did. I've attached a jpg that shows how it looks like in the MPI window.

Jan

[Guido Diepen]

Hi Jan,

not sure about this, but could you see if the default search strategy (i.e. dynamic search) is causing the problem? Unfortunately, not behind a computer with AIMMS at the moment, so can't verify the exact name of the option. There should be something like search strategy under the cplex 12.5 specific options that you can set to the value "branch-and-cut".

Let me know if it does work if you use the branch-and-cut strategy.

Guido Diepen

AIMMS Specialist

[Jan]

Hi Guido,

after setting the search option of clpex to  "branch-and-cut" it is working now, in theory. Thank you a lot for telling me about this option.

The first times Aimms crashed after string the model. Then I played around with the parameter "Maximum number of nodes in search tree" in the Math Program Inspector. Aimms runs fine, when it is set to a value lower than 20. Every higher setting causes a crash. Is it possible that this option is not suitable for viewing thousands of nodes?

Do you have any Idea?

Regards
Jan

[Guido Diepen]

Hi Jan,

not really sure what is causing the crash, but for sure it should not happen ;)

If you can consistently reproduce the crash, could you please create a zip file of the complete project directory (or create an aimmspack) and send it together with the steps to reproduce the crash to our support via support [at] aimms.com? This could help our developers to find out what is the cause of the crash.

Guido Diepen

AIMMS Specialist

[Jan]

Hi Guido,

I will do so. Thank you very much for your help.

Regards
Jan