Jingyue Zhang

Hi David, Specifically, I'm trying to use the shortest path method to create a timetable for flight schedule design. I thought it might be feasible. I read the example you provided, maybe I could u...

Thank you very much！！！！ I tried and it works!

Hi Jaromił, Thank you for your advice again. It's really helpful!!!! I defined the  t[i,f] and tried like this:  for i in range(288):        for f in flights:            tindex[i,f] = 0  try:      ...

Hi Jaromił,  I think I almost got it from the post you shared. It expresses a way to index x[t] andy[t] for Andconstraints. However, I still quite not get how to express the bold part of "For any t...

Hi Nourhan and Eli， I've met similar questions for programming like your code before: for k in blocks:      if k == Kc:         Cont_3=m.addConstr(Z== C*P[k+1]) I'm wondering what exactly are the m...

Hi Jaromił,  your advice is very helpful. I tried and the error disappears. Today I reviewed my code and discovers that the logic might be wrong. The logic I'm trying to express is: 't' stands for ...

Hi Jaromił,  I've tried again using the code like this: try:        m = Model()         x = m.addVars(tof.keys(), lb = 0, ub= 287, vtype=GRB.CONTINUOUS, name='x')         z = m.addVars(tdf.keys(), ...

I got it. I need to set the variables differently so that it would go with the loop for t. Thanks for your time help!!!!

Hi again! I revised the code compression like this:       s  = m.addVar(vtype=GRB.BINARY, name="s")      h  = m.addVar(vtype=GRB.BINARY, name="h")      h2  = m.addVar(vtype=GRB.BINARY, name="h2")  ...

Thanks a lot! However, there was a typing error for the second if-clause, the code is actually:  t = 0        for t in range(288):            for f in tof.keys():                if x[f] <= t and t ...