ILOG CPLEX 11.0 User's Manual

◆◆file reading and writing routines move information from the file system of youroperating system into your application, or from your application into the file system;parameter routines enable you to query, set, or modify parameter values maintained byILOG CPLEX.LicensesILOG CPLEX runs under the control of the ILOG License Manager (ILM). Before you canrun any application program that calls ILOG CPLEX, you must have established a validlicense that it can read. Licensing instructions are provided to you separately when you buyor upgrade ILOG CPLEX. Contact your local ILOG support department if this informationhas not been communicated to you or if you find that you need help in establishing yourILOG CPLEX license. For details about contacting ILOG support, click "CustomerSupport" at the bottom of the first page of ILOG CPLEX online documentation.Compiling and LinkingCompilation and linking instructions are provided with the files that come in the standarddistribution of ILOG CPLEX for your computer platform. Check the readme.html file fordetails.Using the Callable Library in an ApplicationThis section tells you how to use the Callable Library in your own applications. Briefly, youmust initialize the ILOG CPLEX environment, instantiate a problem object, and fill it withdata. Then your application calls one of the ILOG CPLEX optimizers to optimize yourproblem. Optionally, your application can also modify the problem object and re-optimize it.ILOG CPLEX is designed to support this sequence of operations—modification andre-optimization of linear, quadratic, or mixed integer programming problems (LPs, QPs, orMIPs)—efficiently by reusing the current feasible solution (basis or incumbent) of aproblem as its starting point (when applicable). After it finishes using ILOG CPLEX, yourapplication must free the problem object and release the ILOG CPLEX environment it hasbeen using. The following sections explain these steps in greater detail.Initialize the ILOG CPLEX EnvironmentILOG CPLEX needs certain internal data structures to operate. In your own application, youuse a routine from the Callable Library to initialize these data structures. You must initializethese data structures before your application calls any other routine in the ILOG CPLEXCallable Library.To initialize a ILOG CPLEX environment, you must use the routine CPXopenCPLEX.ILOG CPLEX 11.0 — USER’ S MANUAL 111