Hi everybody,
I'm working in a graph optimization problem in which I'm looking for a special kind of tree (actually, I'm dealing with a digraph, looking for a special kind of arborescence).
Some variable used in my formulation are:
1. y_ij: indicating that node j is reached from node i.
2. z_i: indicating node i is leaf.
When looking to solution arcs (those related with variable y_ij), and based on the formulation, it is possible to figure out a custom branch strategy which will lead to 3 children nodes:
1. y_ij = 1; z_i = 0; z_j = 1;
2. y_ij = 1; z_i = 0; z_j = 0;
3. y_ij = 0
How can I deal with that with Cplex? As far as I know, when using method CPXsetbranchcallbackfunc, it is only possible to generate 2 children node for each parent node. Is there any way to overcome that?
Best regards.
Pedro
Topic

Re: Custo Branching Strategies
20130212T17:07:03ZThis is the accepted answer. This is the accepted answer.You can write your branch callback to create two "children", one of which is destined to be split into child 2 and child 3. The instructions for how to split the "metachild" can be attached to the "metachild" as "private data" (via the userhandle argument). I have a diagram here.
Paul
Mathematicians are like Frenchmen: whenever you say something to them, they translate it into their own language, and at once it is something entirely different. (Goethe)