[Scip] Some basic questions

[Gerald Gamrath]

Hi Mehmet,

welcome to the SCIP mailing list!

> 1. which constraints are added in each node. It is same for pricing problem. Somehow, i can get which routes are added in a node, however, i have no idea about in which node they are generated. 
For each constraint handler ( check out SCIPfindConshdlr(),
SCIPgetConshdlrs(), SCIPgetNConshdlrs() ) you can get the array of
constraints of this type by SCIPconshdlrGetConss() and the number of
currently active constraints (globally and locally valid ones) by
SCIPconshdlrGetNActiveConss(). For these constraints, you could check by
SCIPconsGetValidDepth() the valid depth, i.e., the depth of the node in
the tree where this constraint was added and is valid for this node and
the subtree below it. If this constraint was added at the current node,
the valid depth should be the same as
SCIPnodeGetDepth(SCIPgetCurrentNode(scip)).
> 2. any way to visualise tree ( i read there is something vcb, however i didnt understand how to install it) or suggestion (i.e. output format) to get relevant info.
check out http://scip.zib.de/doc/html/FAQ.php#visualizebranchandbound
> 3. how to branch on location variables first ( question came to my mind now, i did not search for it)
You can set the branching priority of your location variables to
something > 0 to always branch on them first. See
SCIPchgVarBranchPriority():
http://scip.zib.de/doc/html/scip_8h.php#a5a932c46db33e505a802313a4b1d973f
> 4. Does a generated route can be used in another node which is not a subsequent node of route's origin node or does it required to be generated again? It doesn't seem so but i want to ask it.
All variables in SCIP are global and can be used in all nodes.

Best,
Gerald