ahmad alanaqreh
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Recent activity by ahmad alanaqreh
Sorry Jaromil, your suggestion is not clear for me, terminating the MP model will terminate the callback which is not what I want, do you mean terminating the DSP model where I am trying to change ...

In my case x[i, j] and z are parameters(alpha, beta, omega, and lamda are variables), actually, these are the values changing every time, so I am changing my objective function based on the new val...

Hi Jaromil Thanks a lot for your answer, yes that is true, in this case how I can replace the objective function?? should I create a new model with a new objective function or there is a way to do ...

Hi Jarmoil I have the following objective function: model.setObjective(quicksum(x[i, j] * alpha[i] for (i, j) in E if i != s) + quicksum((n * (1  x[i, j])  1) * beta[i, j] for (...

Hi Jaromil, this is just the smallest example I have, the time here is acceptable but when the graph has hundreds or thousands of nodes and edges it really takes a lot of time, there is any part th...

Hi Jaromil your suggestion kind of works, the problem that by using the x.VarName it takes x,1,11 to be before x,1,2 in the sorted list !!

Hi Jaromil I am so sorry if the issue was not clear, let me give more details : I have a model where the variable x is defined as follow : x = {}for (i, j) in E: x[i, j] = model.addVar(vtype=GRB....

Hi Matthias I simply do the following : x = {}for (i, j) in E: x[i, j] = model.addVar(vtype=GRB.BINARY, name="x%d,%d," % (i, j)) or x = model.addVars(E, vtype=GRB.BINARY, name='x')

Hi Jaromil That is totally true, moreover, I found that FarkasDual is giving good values but the difference was the sign, I mean if the constraint.FarkasDual is positive constraint.dunbdd is nega...

Hi Jaromil No, I am searching for Farkas Dual because the problem is infeasible, this unbdd is used to get the dual of the constraints if the problem infeasible(called "unbounded dual"): in AMPL i...