Initializing help system before first use

XPRSaddcbnodecutoff

Purpose
Declares a user node cutoff callback function, called every time a node is cut off as a result of an improved integer solution being found during the branch and bound search. This callback function will be called in addition to any callbacks already added by XPRSaddcbnodecutoff.
Topic areas
Callback, Branch and Bound Search
Synopsis
int XPRS_CC XPRSaddcbnodecutoff(XPRSprob prob, void (XPRS_CC *nodecutoff)(XPRSprob cbprob, void *cbdata, int node), void *data, int priority);
Arguments
prob 
The current problem.
nodecutoff 
The callback function, which takes three arguments, cbprob, cbdata and node, and has no return value. This function is called every time a node is cut off as the result of an improved integer solution being found.
cbprob 
The problem passed to the callback function, nodecutoff.
cbdata 
The user-defined data passed as data when setting up the callback with XPRSaddcbnodecutoff.
node 
The node id of the node that is cut off. This id cannot be queried from the CURRENTNODE attribute as for other callbacks since this callback is not invoked in the context of the node being cutoff.
data 
A user-defined data to be passed to the callback function, nodecutoff.
priority 
An integer that determines the order in which multiple node-optimal callbacks will be invoked. The callback added with a higher priority will be called before a callback with a lower priority. Set to 0 if not required.
Example
The following notifies the user whenever a node is cutoff during the tree search: 
XPRSaddcbnodecutoff(prob,Cutoff,NULL,0);
XPRSmipoptimize(prob,"");
The callback function might resemble: 
void XPRS_CC Cutoff(XPRSprob prob, void *data, int node)
{
  printf("Node %d cutoff\n", node);
}
See the example depthfirst.c in the examples/optimizer/c folder.
Further information
1. This function allows the user to keep track of the eligible nodes. Note that the LP solution will not be available from this callback.
2. This callback is invoked only for nodes that are pruned from the active node pool. If the current node gets cut off then the infnode callback is invoked to report this.
Related topics
XPRSremovecbnodecutoff, XPRSaddcboptnode, XPRSaddcbinfnode, XPRSaddcbintsol.

Parent Topic Console and Library Functions

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