Runqiu Hu
PhD Student in Transportation Optimization
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Latest activity by Runqiu Hu
Runqiu Hu commented,
Hello Marika, Thank you for your response. I am not sure whether I follow your idea here, here is my modification: In the noncallback function, set no time limit and call optimize with the callba...

Runqiu Hu created a post,
Solving to optimal within a timelimit, after which terminating at a feasible solution in gurobipy using callbacks
AnsweredHello there, I was trying to solve an MIP using gurobipy. I would like to make the optimization two steps: 1. For the first 7200 seconds, solve exhaustedly to optimal; 2. If no feasible solution is...

Runqiu Hu commented,
Hello, Shukla, Actually, you just have to call m.optimize() after m.read(). I tested your code, and can obtain the result now. Sorry for my misleading in the previous post on "removing the model.op...

Runqiu Hu created a post,
Questions on the mechanic of the hierarchical method for multiobjective optimization
AnsweredHello, I would like to know how the hierarchical method for multiobjective optimization works. For example, I have 2 objectives here: min obj1 and min obj2. The priority for obj1 is set to 10 and ...

Runqiu Hu commented,
Hello Michael, I received an email notification and saw you mentioned my post for a similar question before. Actually, after my attempt later, I found that even only reading the result value from a...

Runqiu Hu created a post,
Time indexed based vehicle routing problem under given time budget
AnsweredHello, I am modeling a problem of vehicle routing problem under a given time budget. Specifically, I discretized the time budget (e.g., 3 hours) into T intervals with equal length (e.g., 9 interval...

Runqiu Hu created a post,
Is it possible to retrieve variables as tuplelist outside the model definition scope in gurobipy?
AnsweredHello, I'm using gurobipy to solve a model. Now I would like to make the definition of the model (variables, constraints, and objectives), and the output of the result in separate functions in ord...

Runqiu Hu commented,
I'll summarize the steps below of my method on saving the model and read solutions directly without taking long time to run again. 1. create a model m 2. add variables, set objectives and constrain...

Runqiu Hu commented,
Thanks Matthias. Actually, I've tried using the SOL file with codes in another post. gv = m.getVars() names = m.getAttr('VarName', gv) for i in range(m.SolCount): m.params.SolutionNumber = i ...

Runqiu Hu created a post,
How to save a complete solution of an already executed and solved model which allows to load next time without executing again?
AnsweredHello, I am using gurobipy to solve a model. I would like to know if it is possible to save the executed result of a model as a whole, which can be loaded next time for result processing or for som...