Questions tagged [or-tools]
Questions related to or-tools, Google's open-source software suite for optimization
176
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TSP problem using Google's OR tools
This is the Travelling Salesperson Problem code from Google's OR tools. I used a simple instance that is defined in the data dictionary and has optimal value (sum of Euclidean distances) of 36.26 for ...
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how the number of employees affects the married employee scheduling problem
My scheduling problem has a specific pattern of 2 days of work followed by 2 days off. Additionally, there is a week off after every 4 weeks of work. The scheduling matrix (P) has five different ...
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Routing problem - How can I make use of the Clarke and Wright algorithm for a CVRP, when using the ortools library?
TL;DR: How can I specify to ortools to use only the Clarke and Wright algorithm.
Hello,
I'm trying to solve a CVRP. When exploring the my options, I stumble by the ortools library, it gets the job ...
- 73
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262
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how to count the number of values that are greater than zero in OR-Tools
I am using OR-Tools for an employees scheduling problem. I have a dictionary that is defined as an IntVar, where such dictionary contains the number of hours that will be assigned to each employee, ...
- 31
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2
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535
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Does OptaPlanner give equally good results when comparing with commercially available MIP solvers?
I want to solve a Mixed Integer problem with several constraints. Gurobi or Google OR tools solve such problems. Though I am not sure, I think they use an exact method such as branch and bound or ...
- 123
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152
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Constraint programming problem with matrix of integers
I am trying to solve the following problem. Suppose $A$ is an $m \times n$ matrix of integers with entries in $\{1, \dots, k\}$. There are two kinds of constraints on the entries of this matrix:
For ...
2
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1
answer
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What exactly does the AddHint() method in Google OR-Tools' CP-SAT solver do?
I have an optimization problem that I am solving with CP-SAT and I am using the Python interface. Moreover, I know a good feasible solution coming from a heuristic and I want the solver to start its ...
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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 ...
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1
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792
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About circuit constraints in OR - tools
I am trying to implement a scheduling problem to solve with CP-SAT from OR-tools. There, in particular, for every machine I want to add a time transition constraint from every task that is performed ...
- 199
3
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CP-SAT's `NumBooleans()` parameter
The solver API for CP-SAT offers the attribute NumBooleans, which is documented as "Returns the number of boolean variables managed by the SAT solver".
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- 181
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Alternative Approaches to Assignment Problem
I have a real world use case where I aim to optimize the assignment of trucks to orders of different sizes over a time window by minimizing some cost function (e.g. total distance traveled).
The below ...
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153
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Reformulate this constraint optimization problem such that I do not have to divide 2 variables?
I have a constraint optimization problem as follows:
I need to assign $m$ tasks to $n$ days, with $n \geq m$.
Each day can host 0 to $m$ tasks.
Each task either belongs to type $A$ or $B$.
I want to ...
- 19
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answer
389
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Relevance of order of model construction in CP-SAT
Question 1: Is ortool's CP-SAT sensitive to the order in which a model is constructed?
In other words, does it matter which variables and constraints come first?
I am seeing a high performance ...
- 181
1
vote
1
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83
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Multiplicity-Constraint in Constraint Programming Solvers
I need to solve a CSP with a constraint imposing upper bounds on the multiplicity of variables in a list.
More precisely, I need a constraint of the form
...
- 113
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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 ...
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