Originally posted by: QINGQINGQING

dear all

I am now using cplex to handle MIP with java, and I get a problem

IloCplex cplex = new IloCplex();
int D=2;
IloNumVar[] x=new IloNumVar[D];//x[i]
for(int i=0;i<D;i++){
x[i]=cplex.numVar(0, 1, ilog.concert.IloNumVarType.Bool);//bool variables
}
IloLinearNumExpr expr= cplex.linearNumExpr();
for(int i=0;i<D;i++){
expr.addTerm(x[i], 1.0);//x[1]+x[2]
}
cplex.addLe(expr, 1);//x[1]+x[2]=1
IloLinearNumExpr obj = cplex.linearNumExpr();
for(int i=0;i<D;i++){
obj.addTerm(x[i], 3.0);//3 * (x[1]+x[2])
}
System.out.println(expr);
cplex.addMaximize(obj);//max{3 * (x[1]+x[2])}
cplex.solve();
for(int i=0;i<D;i++){
if(x[i].equals(0)){
System.out.println(x[i]);
}
if(x[i].equals(1)){
System.out.println(x[i]);
}
}

the result is

1.0*http://0..1 + 1.0*http://0..1
Tried aggregator 1 time.
MIP Presolve eliminated 1 rows and 2 columns.
All rows and columns eliminated.
Presolve time = 0.00 sec.

and I would like to know the reason to why no solution is available, would you help me?

Thank you
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: QINGQINGQING

I check out the variable x[i], and it always http://0..1
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: QINGQINGQING

I check out the variable x[i], and it always [0..1]
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

Please see the section

IBM ILOG CPLEX Optimization Studio V12.2 > CPLEX > User's Manual for CPLEX > Languages and APIs > Concert Technology for Java users > Accessing solution information

in the CPLEX documentation.

/Paul

Mathematicians are like Frenchmen: whenever you say something to them, they translate it into their own language, and at once it is something entirely different. (Goethe)
#CPLEXOptimizers
#DecisionOptimization