Questions tagged [or-tools]
Questions related to or-tools, Google's open-source software suite for optimization
24
questions with no upvoted or accepted answers
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198
views
OptionalIntervalVar enforced but not working OR-TOOLS
I'm using OptionalIntervalVar and then maximizing the starts. The optimal solution is not affecting the other variables that creates the ...
6
votes
0
answers
151
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Modelling issue with precedence constraint in OR-Tools
I'm trying to solve an RCPSPDc model It is infeasible, although Ilog Cplex solves it, so I think I have a modelling issue. I have more constraints but the precedence is the one that makes it ...
4
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answers
431
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Google-OR tools vs Pyomo and other commercial Solvers for solving a simple maximum flow problem
I have implemented a Pyomo model for solving maximum flow problem as a subroutine of an algorithm. However, the approach does not scale very well because Pyomo does not provide a very good way to re-...
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4
votes
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answers
100
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Modelling issue with rcpsp and boolean expressions
I'm trying to solve an RCPSPDc problem in OR-Tools with CP-SAT solver.
In my RCPSPDc model (with discount rate) i want to set this objective:
$$\max_{s}\sum_{j\in J}\text{profit}_{j}\cdot \frac{1}{(1+...
3
votes
0
answers
150
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Or-tools : CVRP multiple time window with multiple location
I am using or-tools to solve a CVRP with multiple time window, and multiple location.
Meaning that a customer can move during the day.
I can't achieve to add constraint like if i deliver the customer ...
- 31
3
votes
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answers
141
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Can Pyomo be linked with Google's GLOP or CP-SAT solvers?
Pyomo can be linked with several solvers Open source and commercial ones.
I was wondering if Pyomo can be linked with Google's GLOP or CP-SAT solvers?
- 1,120
3
votes
0
answers
364
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Incorporating OR-Tools in a CMake Project
I'm trying to incorporate or-tools into my cmake project.
I've tried some of the suggestions given by the project maintainers, who give a few different ways to integrate or-tools in the readme and in ...
- 431
3
votes
0
answers
389
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Circuit constraints in ortools
I am looking to assign tasks to people. Each successive task should be started after the first one is finished and should be started at the same location as the preceding task. While the time ...
3
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227
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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 ...
- 131
3
votes
0
answers
110
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Production planning for a video game economy
I'm a software developer who likes to play a video game that has a complex economy. I realized that the type of problem I'm trying to solve mimics real life operations research problems, and I am ...
- 139
3
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140
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Best known results on the flexible jobshop benchmarks
Is there a website that compiles the best known results on the flexible jobshop problem ?
I know there was a blog post/article by Quintiq, a (deleted) blog post on CP Optimizer, some more recent ...
- 2,219
3
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answers
49
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High-mix manufacturing capacity
I'm not an expert in OR but I would like to determine what is the maximum manufacturing capacity of a plant (or how much a plant can produce of mix products).
Each person in the plant has a known set ...
- 31
3
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0
answers
175
views
Power of variable or tools
I'm working with OR Tools in Python and I need to define the objective function an expression of the variables. In particular, the objective function is
$$\frac{c_j}{1.7^{s_j}}$$
with $c_j$ ...
- 131
2
votes
1
answer
238
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OR-Tools: Nonlinear constraints?
I have inherited a reasonably simple ortools-based optimizer (Python) with linear relationships that I need to non-linear-ize, and I have no idea how to do that.
The relevant part of my problem looks ...
- 121
2
votes
1
answer
80
views
Control load per trip in multi trip VRP in ORTools
I have implemented multitrip VRP in ortools (To be specific, solved CVRPTW with virtual depots). Maximum number of trips per vehicle is limited to 2. I want to put a hard constraint that load carried ...
- 181
2
votes
0
answers
128
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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:/...
- 21
2
votes
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answers
408
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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
0
answers
85
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Minimizing total number of banners used in the cover buildings problem modelled
I was watching a video about Google OR-Tools where they were solving this cover building problem from Codility challenges using constraint programming.
In short, you have a list of building heights, e....
- 111
1
vote
0
answers
264
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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..!
- 137
1
vote
0
answers
168
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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 ...
- 153
1
vote
0
answers
185
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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:
...
- 111
0
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0
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348
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OR-Tools addElement constraint
I am just not able to grasp how can I use the addElement constraint of OR-Tools. I am trying to model the following constraint written in MiniZinc:
...
- 119
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126
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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 ...
- 137
-1
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1
answer
91
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[OR-Tools][CP-SAT] Implement an indicator function in a constraint
Good morning ! I would like to implement this constraint using CP-SAT (see image below).
x_i,j is a boolean variable, a and b are given. The problem is that I don't know how to implement the ...
