ILOG CPLEX 11.0 User's Manual

Considering Preliminary IssuesWhen you are optimizing a MIP, there are a few preliminary issues that you need to considerto get the most out of ILOG CPLEX. The following sections cover such topics as enteringvariable types, displaying MIPs in the Interactive Optimizer, detecting the problem type, andswitching to the fixed form of your problem.◆ Entering MIP Problems on page 257◆ Displaying MIP Problems on page 258◆ Changing Problem Type in MIPs on page 259◆ Changing Variable Type on page 260Entering MIP ProblemsYou enter MIPs into ILOG CPLEX as explained in each of the chapters about the APIs ofILOG CPLEX, with this additional consideration: you need to indicate which variables arebinary, general integer, semi-continuous, and semi-integer, and which are contained inspecial ordered sets (SOS).Concert Technology users can specify this information by passing the value of a type to theappropriate constructor when creating the variable, as summarized in Table 14.1.Table 14.1Specifying Type of Variable in a MIPType of Variable C++ API Java API .NET APIbinary IloNumVar::Type::ILOBOOL IloNumVarType.Bool NumVarType.Boolinteger IloNumVar::Type::ILOINT IloNumVarType.Int NumVarType.Intsemi-continuous IloSemiContVar::Type::ILONUM IloNumVarType.Float NumVarType.Floatsemi-integer IloSemiContVar::Type::ILOINT IloNumVarType.Int NumVarType.IntCallable Library users can specify this information through the routine CPXcopyctype.In the Interactive Optimizer, to indicate binary integers in the context of the entercommand, type binaries on a separate line, followed by the designated binary variables.To indicate general integers, type generals on a separate line, followed by the designatedgeneral variables. To indicate semi-continuous variables, type semi-continuous on aseparate line, followed by the designated variables. Semi-integer variables are indicated bybeing specified as both general integer and semi-continuous. The order of these threeILOG CPLEX 11.0 — USER’ S MANUAL 257