Dear All,
Good day to you.
As a background, my objective of MILP case is to minimize the lead time (obj_lambda)
by using docplex.mp only.Supposing the decision variables for the minimizing the lead time are several x in X as model.integer_variables with several constraints.
Then, I also would like to sort the decision variables x in X into s in S as model.integer_list_variables for the next constraints. In short, S is X.sort().
Based on my manual calculation, the obj_lambda is 270 and the value of x should be different each other in range of 2 to 270, for example: 2,...,100, and 270.
I have tried 4 scenarios by using Pycharm
(all files are attached and named respectively).File A: Running the CPLEX by defining S = np.array(np.sort(x))
Result:
obj_lambda=310.000 ,
obj_lambda=310.000
x2=2.000
x3=103.000
x4=105.000
x5=306.000
x6=308.000
no result for S
File B: Running the CPLEX by defining S just as S[k] = mdl.integer_var(lb= 0, ub= inf, name='S' + str(k+1))
Result: objective: 207
obj_lambda=207
x1=8
x2=10
x3=4
x4=6
x6=2
S2=2
S3=4
S4=6
S5=8
S6=10
File C: Running CPLEX by using the example from:
howtowithdocplex/sortdecisionvariablesMP.py at main · AlexFleischerParis/howtowithdocplex and combine into 1 Model. (S = y_temp.reshape(Total_T,1))
Result: objective: 207
obj_lambda=207
x1=8
x2=10
x3=4
x4=6
x6=2
S_1=2
S_2=4
S_3=6
S_4=8
S_5=10
File D: Running CPLEX by using the example from:
howtowithdocplex/sortdecisionvariablesMP.py at main · AlexFleischerParis/howtowithdocplex and use 2 Model within the same coding. (mdl = Model(name='Scheduling') and mdl2 = Model(name='sortvariables').
Result:
Error: docplex.mp.utils.DOcplexException: Cannot mix objects from different models in new_binary_constraint. obj1=x_temp_0, obj2=x1
In this case,
1. is it impossible if we have two Models run within the same python coding but still with the same main objective ? (Model 1 (main objective) for minimizing and Model 2 for sorting for the respective constraints) ?
2. Given I would like to get
the minimum obj_lambda, x in X, and s in S, could anyone help me, please?
Here is the original objective function and constraints.
#DecisionOptimization