Questions tagged [coin-or]
For questions relating to the Computational Infrastructure for Operations Research (COIN-OR).
9
questions
2
votes
1
answer
87
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Structuring an MINLP solver
Folks, I am working on a project in which I have to code some C++ algorithms for smooth MINLPs.
Such algorithms are Extended Cutting Plane, Extended Supporting Hyperplane, and Outer Approximation. I ...
- 1,091
6
votes
1
answer
458
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Using CBC CLI Arguments in Pyomo
I am currently using the cbc solver with Pyomo
opt = SolverFactory('cbc')
opt.solve(model)
How can more options for Cbc be used,...
- 243
3
votes
0
answers
92
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Extract/Inject Solutions (orig problem-space) during Search in MILP -> CoinOR Cbc
Task / Goal
I'm considering adding some customized problem-specific local-search component on top of a general-purpose MILP solver (= improvement heuristic).
The basic idea is the following:
All new ...
- 405
24
votes
4
answers
11k
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What are the advantages of commercial solvers like Gurobi or Xpress over open source solvers like COIN-OR or CVXPY?
I come from an ML background, and occasionally have to dive into the OR world. I am trying to figure out whether I need to purchase a commercial solver license for a certain problem set.
In the ML ...
- 2,089
4
votes
1
answer
235
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Deterministic termination criteria for CBC
I'm running CBC on problems for which not always an integer solution can be found in a given time, so the command line option sec 120 is set (2 minutes maximum). ...
- 141
3
votes
1
answer
255
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Manually indicate initial basis for coin-or lp solver CLP
I have a set partitioning formulation with each constraint being an equality constraint to meet the given demand (right-hand side of the constraint).
For each constraint, I have a slack and a surplus ...
- 31
8
votes
1
answer
688
views
Creating a Continuous Decision Variable between 0 and 1 in Python-MIP Interface
This task appears to be harder than it seems to me.
I want to create a continuous variable $x \in [0,1]$.
To test this, I did use the open-source Python-MIP interface which uses the CBC-Solver out ...
- 1,193
8
votes
1
answer
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How to set a maximum time to improve a solution with Pyomo and CBC
In relation to using CBC via Pyomo:
I was wondering if anyone knew if it was possible to set a maximum allowed time to improve a solution, rather than a maximum total time. This way, if you've been ...
- 421
5
votes
2
answers
402
views
Installing COIN-OR solvers in Ubuntu (Azure)
For a side project, I'm looking to install COIN-OR project solvers on a Microsoft Azure Ubuntu VM. (I will be running Pyomo optimization models on this VM as well; using NEOS isn't cutting it.) ...
- 371