Questions tagged [or-tools]
Questions related to or-tools, Google's open-source software suite for optimization
178
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Most constraining constraint CP-SAT
I am using CP-SAT to minimize a problem similar to Flexible Job Shop Scheduling (https://github.com/google/or-tools/blob/stable/examples/python/flexible_job_shop_sat.py), with a minimization objective....
2
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1
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99
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How to reset hints in a CP-SAT model?
Pretty much the title. I have a cp model for which I have already provided a hint when minimizing a given objective function. I now want to provide a new hint to minimize the model with respect to a ...
- 221
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40
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Job Shop Scheduling with Multiple possible machines for a task in CP-SAT
I am trying to convert the job shop scheduling example of CP-SAT, which goes as;
Below is a simple example of a job shop problem, in which each task is labeled by a pair of numbers (m, p) where m is ...
- 19
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How to request shifts when nurses _don't_ work
So I am working on a variation of the nurse scheduler.
This includes then the ability to have nurses request when they are going to be on...
However, I need to be able to support requests for when ...
- 101
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52
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Convert sequence to succession matrix with CP-SAT
Say I have a sequence [3,1,0,2], where each element is a decision variable, i.e. I decide upon an optimal sequence of numbers. Is there an appropriate way to convert this sequence to a 2D succession ...
3
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834
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How to avoid similar solutions?
I have a problem like this
$x_1 +x_2 +x_3 =10$
let's assume $0 \leq x_i \leq 10$
It is obvious that this problem has more than one solution
For example :
Solution 1 : $x_1 =0 , x_2= 1 , x_3 =9$
...
- 1,378
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86
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Cumulative constraint with a window
I have a decision variable R, indexed by n over N, where R[n] is equal to some integer value. I want a constraint that, for a specific window size, e.g. 5, gives a maximum to the summed values inside ...
2
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121
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Optimizing a Route Selection Problem with Multiple Constraints and Objectives
I'm developing a solution to optimize a vehicle routing problem where each stop has an associated score (priority), specific geo coordinates, and a required stop duration. The goal is to maximize the ...
- 131
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97
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Assignment of colored boxes to groups
I am working on a problem that I think can be solved as an extension to the assignment problem, but am open to hear about other ways to solve.
PROBLEM
There are a lot of colored boxes. For each color ...
- 23
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97
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Information shared among workers in OR-tools CP-SAT
I stumbled upon this video while using OR-Tools CP-SAT solver
https://www.youtube.com/watch?v=lmy1ddn4cyw
At around 12:10, the part of multithreaded solvers starts. I understand these solvers are ...
2
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1
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260
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CP-SAT: Workarounds for OnlyEnforceIf with Linear Expressions
Background
I've written a solver that selects a subset of people from a larger pool such that the subset has at least X people per attribute (Gender/Job/Country etc. X differs per attribute).
This ...
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86
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Vehicle Routing Problem OR-tools - Distance between solutions / vehicles
I have an alternative problem which I reckon can be solved using OR-tools. For this problem, apart from the distance between nodes within a solution, I also need the distance between the n-th node of ...
- 19
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115
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Solving a weighted XOR-SAT problem
I want to solve a variant of the weighted XOR-SAT problem. Concretely,
Given $n$ boolean variables $x_1,\ldots,x_n$ each of which is assigned a non-negative cost $c_1,\ldots,c_n\in\mathbb{R}_{\ge 0}$ ...
- 123
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86
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Implementing soft time window constraints with time_matrix dependent on vehicle types
I am solving a CVRPTWPD using Google ORTools. Here, objective is to minimize the travelled distance and not time.
I have start locations for each vehicle but arbitrary end locations are possible. I ...
- 211
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130
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How to set the parameters for GLOP for a DUAL_FEASIBLE case
Now I have a linear programming model, I have tried to formulate this model with or-tools, and then solve it with the GLOP but failed.
After reaching the 15-minute time limit, the status of GLOP is ...
- 105