CPXgetcallbackseqinfo

Note

This is an advanced routine. Advanced routines typically demand a thorough understanding of the algorithms used by ILOG CPLEX. Thus they incur a higher risk of incorrect behavior in your application, behavior that can be difficult to debug. Therefore, ILOG encourages you to consider carefully whether you can accomplish the same task by means of other Callable Library routines instead.

The routine CPXgetcallbackseqinfo accesses information about nodes during the MIP optimization from within user-written callbacks. This routine may be called only when the value of its wherefrom argument is CPX_CALLBACK_MIP_NODE. The information accessed from this routine can also be accessed with the routine CPXgetcallbacknodeinfo. Nodes are not stored by sequence number but by node number, so using the routine CPXgetcallbackseqinfo can be much more time-consuming than using the routine CPXgetcallbacknodeinfo. A typical use of this routine is to obtain the node number of a node for which the sequence number is known and then use that node number to select the node with the node callback.

Note

This routine cannot retrieve information about nodes that have been moved to node files. (For more information about node files, see the ILOG CPLEX User's Manual.) If the argument seqnum refers to a node in a node file, CPXgetcallbacknodeinfo returns the value CPXERR_NODE_ON_DISK.

A pointer to the CPLEX environment, as returned by CPXopenCPLEX.

The pointer passed to the user-written callback. This argument must be the value of cbdata passed to the user-written callback.

An integer value indicating where the user-written callback was called from. This argument must be the value of wherefrom passed to the user-written callback.

The sequence number of the node for which information is requested.

An integer indicating which information is requested. For a summary of possible values, refer to the table titled Information Requested for a User-Written Node Callback in the description of CPXgetcallbacknodeinfo.

A generic pointer to a variable of type double or int. The variable represents the value returned by whichinfo. The column C Type in the table titled Information Requested for a User-Written Node Callback indicates the type of various values returned by whichinfo.

The routine returns zero if successful and nonzero if an error occurs. The return value CPXERR_NODE_ON_DISK indicates an attempt to access a node currently located in a node file on disk.

CPXgetcallbackseqinfo

Parameters:

Returns:

env	A pointer to the CPLEX environment, as returned by `CPXopenCPLEX`.
cbdata	The pointer passed to the user-written callback. This argument must be the value of `cbdata` passed to the user-written callback.
wherefrom	An integer value indicating where the user-written callback was called from. This argument must be the value of `wherefrom` passed to the user-written callback.
seqid	The sequence number of the node for which information is requested.
whichinfo	An integer indicating which information is requested. For a summary of possible values, refer to the table titled Information Requested for a User-Written Node Callback in the description of `CPXgetcallbacknodeinfo`.
result_p	A generic pointer to a variable of type `double` or `int`. The variable represents the value returned by `whichinfo`. The column C Type in the table titled Information Requested for a User-Written Node Callback indicates the type of various values returned by `whichinfo`.