Questions tagged [or-tools]

Questions related to or-tools, Google's open-source software suite for optimization

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2
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1answer
468 views

How to know which constraint in CP-SAT did not meet the feasibility gap

Is there any systematic way to retrieve some information on the constraint that caused infeasibility in Or.Tools CP-SAT? ...
2
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1answer
72 views

Extracting CNF representation of my problem from SAT solver

As I know, any SAT solver such as or-tools or cplex cp optimizer converts a given problem to CNF form in the first place. Is it possible to extract the resulting CNF representation from or-tools or ...
2
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1answer
96 views

How to model a set of integer variables getting assigned different values than another set of integer variables

Assume we have variables $x_1, x_2, x_3, x_4$ that each can belong to $\{1,2,...,10\}$. How can we model a constraint that variables $x_1, x_2$ get assigned different values than $x_3, x_4$? Because ...
2
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0answers
99 views

Multiple Depot/Crew Office Bus Driver Scheduling Modelling

I'm working on Bus Driver Schedule with multiple add-on constraints that are complex and hence trying to figure out how this can be achieved. Reference of Bus Driver Scheduling using OR-Tools:- https:/...
2
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0answers
43 views

Add Variables in Bulk for ortools

I am using the Python ortools to solve large LPs where the number of variables and constraints are in the hundred thousands ($10^5$). Surprisingly, it takes longer ...
2
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0answers
178 views

modify pickup and delivery problem to only delivery scenario in google OR-tools

I am using Google OR Tools for solving the capacitated vehicle routing problem.I want to implement optimization solution for delivery problem.For example there is one storage location which load all ...
1
vote
1answer
154 views

Travelling salesman problem variant without returning to the starting point

I tried the code provided on the link : https://developers.google.com/optimization/routing/tsp The actual requirement is to traverse all paths without returning to the start point with minimum ...
1
vote
1answer
97 views

Problem with setting up gurobi with OR-tools

I am trying to setup Gurobi with Google OR-Tools with the function pywraplp.Solver.CreateSolver("GUROBI"). The function returns None, which could occur if ...
1
vote
1answer
139 views

How to balance the workload of teachers in OR-Tools (maximization of the minimum)

I am very new to optimization and OR-Tools. I am trying to solve a very simple question. Let's assume that we have $n$ students. Each student needs to be assigned to only one teacher as a supervisor. ...
1
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1answer
69 views

CP-SAT _ Summing variables under conditions

I have been working lately on scheduling optimization using CP-SAT in OR-TOOLS and now I'm at the point where I need to start considering due dates in my model. I didn't want to put them as ...
1
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1answer
52 views

Print Intermediate Solutions of Scheduling Problem and tackling FLAGS in jupyter notebook

I tried this code and it goes on and I'm clueless when it'll end so I manually interrupt it. Is there any way we can see intermediate solutions that are feasible solutions and can we limit time or ...
1
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1answer
130 views

Flexible Job Shop Problem with several resources per alternative - Ortools

It has been quite a journey for me to go from 0 to understanding the job shop (js) and the flexible job shop (fjs) examples given by Google's ORTOOLS team. Now the time has come for me to start ...
1
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0answers
55 views

Modified bus scheduling problem question in ortools

Has been crossposted in stackoverflow. I want to solve the bus scheduling problem using ortools with some minor modifications. In my case, the max number of drivers is known. The modifications I would ...
1
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0answers
71 views

Fixed cost associated to SlackVar(waiting time cost) [CVRPTW]

I'm modeling a CVRPTW with some features: Each type of vehicle has a cost per km and a fixed cost per trip. To calculate these costs, I am using these methods for this: ...
0
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0answers
111 views

Set Covering and Column Generation

I need some set covering and column generation examples in OR-Tools python. If anyone can provide or direct me to some resources that would be great..!
0
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0answers
89 views

Mixed Integer Programming - Model Formulation for A Resource Allocation Problem

There are a number of orders, which needs to be shipped. For each order, there may be 1 to 3 route options. The problem here is to find out the best allocation (combination) of orders among these ...

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