[eclipse-clp-users] Eplex

Hello,

 

I am trying to solve a MILP problem using Eplex invoked from CLP. The
optimization variables are Boolean variables but because the ILP equivalent
problem is hard to solve it in a reasonable amount of time I decided to do
some relaxations.

 

Now I have an example where if I am trying to solve the ILP problem it takes
around 120 seconds. I was thinking to force eplex to see only some Boolean
variables as integers and the others as float numbers in order to check if I
can get an suboptimal solution faster.

I have seen that in general this is not the case. Solving the ILP can be
faster than solving the MILP.

 

Can someone please explain to me this behavior? I attached my clp code.

Thanks,

Bogdan.