liu heng

Suppose m is the original model and p = m.presolve() If I do some modifications on p (e.g. optimize or modify variable bounds), will the original model be modified?

Assume the original model m has 100 variables, and I fix 30 of the 100 variables by setting v.UB=1 , v.LB=1. I want to get the corresponding model with 70 variables. However, if I call p=m.presolve...

Suppose "sol" is a list that consists of the value of each variable.(sol is given by user) How to compute the objective and feasiblity of sol

Suppose I manually give a solution by setting v.Start = xxx. Then I call m.optimize() and the log only shows that "Loaded user MIP start with objective xxx". Does it means the solution is feasible?

How do Precrush and  AggFill/Aggregate affect variables?(introduce new vars or remove vars)

In m.optimize(),  a presolved model p is generated and solved, then the solution of p is automatically mapped back to m. Can I stay at the state where p is generated but not solved? I want to try s...

Suppose model_1 is read from file. model_2 = model_1.copy() if i modify model_2（fix variables or add constraints）, will model_1 still keep the original form?

I have a current solution 'sol_0' and set v.Start as the current value, then i fix some of the variables and solve the model. In the presolve stage, all rows and columns are removed but i still get...

I want to try many kinds of fixations of the original model m and solve it. However, the optimization of m take much time on presolving. So i want to presolve m first(only once) and then do the fix...

  How to fix some variables of model m after m is presolved, and obtain a solution of the corresponding sub-MIP. I tried to fix some variables of model p  = m.presolve() and solve it, however, p ma...