The routine CPXsetlpcallbackfunc modifies the user-written callback routine to be called after each iteration during the optimization of a linear program, and also periodically during the CPLEX presolve algorithm.

Callback description

 int callback (CPXCENVptr env,
               void       *cbdata,
               int        wherefrom,
               void       *cbhandle);
 

This is the user-written callback routine.

Callback return value

A nonzero terminates the optimization.

Callback arguments

env

A pointer to the CPLEX environment that was passed into the associated optimization routine.

cbdata

A pointer passed from the optimization routine to the user-written callback function that identifies the problem being optimized. The only purpose for the cbdata pointer is to pass it to the routine CPXgetcallbackinfo.

wherefrom

An integer value specifying from which optimization algorithm the user-written callback function was called. Possible values and their meaning appear in the table below.

cbhandle

Pointer to user private data, as passed to CPXsetlpcallbackfunc.

Parameters

env

A pointer to the CPLEX environment as returned by CPXopenCPLEX.

myfunc

A pointer to a user-written callback function. Setting callback to NULL prevents any callback function from being called during optimization. The call to callback occurs after every iteration during optimization and periodically during the CPLEX presolve algorithms. This function is written by the user, and is prototyped as documented here.

cbhandle

A pointer to user private data. This pointer is passed to the callback function.

Example

 status = CPXsetlpcallbackfunc (env, myfunc, NULL);