Mario Ruthmair

Hi Micah, Have you tried to remove parameter Method=0? This forces the primal simplex to be used which is in most cases not a good idea. In your case the primal simplex gets quite stuck when solvin...

If the LP subproblem is infeasible, then it is of course not possible to retrieve a feasible solution via attribute X. You should set the following parameter for your subproblem to get a clearly de...

Additionally, since variable index k defines a vehicle type and not a single vehicle, the capacity constraint for one particular k is too restrictive since it sums up the demands served by all vehi...

Since I just stumbled over this old thread:Note that there are constraints missing that eliminate vehicle subtours that are separated from the depot.There are many ways to do that, using Big-M cons...

Hi Mina, I guess your subproblem is an pure LP, right?Did you set parameter InfUnbdInfo=1 to get the UnbdRay attribute?Additionally, you might set DualReductions=0 to be sure that the model is unbo...

Hi Mario, You do not necessarily need the calls to update(), but apart from that this is the way to go. Best regards,Mario

Hi, This is indeed strange, the default setting should be LPWarmStart=1 which means that presolve is disabled and the start basis is used. Apart from that, you probably want to set LPWarmStart=2 in...

This is similar to before: You are working with MVars but want to store an expression in a QuadExpr. You need to use either an MQuadExpr or work with Vars instead of MVars. MQuadExpr are temporary ...

Hi Frank, Did you already try to follow the suggestions in this article about how to find out why some model is infeasible? Best regards,Mario

Hi Bushido, QuadExpr does not support MVars. In particular, if x is an MVar, then x[i,j] is a 0-dimensional MVar, not a Var object. You could fix this in several ways: You keep the MVar but use th...