Hi everyone,
i'm thinking to add into the struct

struct IOSNPD

a new field named unique_id  into the header file glpios.h

Another question, wher i can add the implementation of the function
int glp_ios_unique_id_node(glp_tree *T, int p);

Which this new field and new function i could give a name for each node and
i can build the tree.
Is it a silly idea?




2010/2/24 Guerino Iacobucci <[email protected]>

> Hi Mr. Makhorin,
> i'm just thinking which i can comment this code line which call the
> function :
>
>       ios_delete_node(tree, p);
>
> in this point:
>
> fath: /* the current subproblem has been fathomed */
>       if (tree->parm->msg_lev >= GLP_MSG_DBG)
>          xprintf("Node %d fathomed\n", p);
>       /* freeze the current subproblem */
>       ios_freeze_node(tree);
>       /* and prune the corresponding branch of the tree */
>       ios_delete_node(tree, p);    <------###########
>       /* if a new integer feasible solution has just been found, other
>          branches may become hopeless and therefore should be pruned */
>       if (mip->mip_stat == GLP_FEAS) cleanup_the_tree(tree);
>
>
> if i do that there are side effects or it is the right way?
>
> Excuse me for my ignorance but i really don't understand by reading the
> reference how and which parameter
> i can give to the callback function, could you give an example?
>
> Kind Regards,
> IG
>
>
> 2010/2/24 Andrew Makhorin <[email protected]>
>
>> > Well, there is any way to obtain the entire list of nodes and build
>> > the tree?
>>
>> Currently such a feature is not supported.
>>
>> > Is possible to modify the B C api #39;s to obtain that list?
>>
>> In principle, yes. You can trace each new node of the tree in the
>> the callback routine specifying it in the parameter list passed to
>> glp_intopt. For more details please see the glpk reference manual
>> included in the distribution.
>>
>> Another way is to patch the glpk source code (see the routine
>> ios_driver in file src/glpios03.c). See also the BAK package
>> developed by Brady Hunsaker, which allows visualizing the search
>> tree for three mip solvers including glpk:
>> http://www.rosemaryroad.org/brady/software/index.html
>>
>>
>
_______________________________________________
Help-glpk mailing list
[email protected]
http://lists.gnu.org/mailman/listinfo/help-glpk

Reply via email to