Originally posted by: Cagri

Hello,

I study on a MIP model with IBM ILOG OPL 6.3 and I define the decision variables as int+ or float+. But, still I have very small negative solution values for these decision variables. Also, when I try to change some constraints, I confronted with some relaxation values such as -33000:Infinity. But, I know that the MIP model works well and these values must be in 0:Infinity.

Do you know, what I am supposed to do and what the problem is?

Cagri SEL
#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi

if you want to forbid a possible relaxation then you should write an unlabeled constraint in the subject to block.

For example if you do not want x to be negative just write

x>=0;

in the subject to block

regards

Alex
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: Cagri

Thank you Alex. It was helpful to understand relaxation process.
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: Cagri

Thanks
#DecisionOptimization
#OPLusingCPLEXOptimizer