Questions tagged [julia]
For questions about solving Operations Research problems using the Julia programming language.
13
questions
3
votes
1
answer
109
views
How to remove a callback that was previously registered in Julia?
I'm coding in Julia, how can I do the same as "Remove(Cplex.Callback)" function does in C++ ?
- 173
5
votes
4
answers
200
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What are the key pros and cons to mention when asked why one prefer Julia over Python in OR-research-industry interviews and vice-versa?
I want to apply for a position after my PhD in an industrial laboratory that does research in OR.
They stipulate that they want either Python or Julia programming languages. Since my Bachelor's ...
- 583
3
votes
1
answer
75
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Reoptimization with GLPK in Julia/JuMP
I've been looking everywhere, and I can't seem to find any information on whether GLPK can do successive optimizations on the same model, on which we add a constraint at each iteration.
More ...
- 33
2
votes
1
answer
37
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How to get the fractional solution of a node in a MIP model using JuMP package?
I'm coding in Julia and use the JuMP package. My IP solver stops by a fixed node limitation. I noticed that I can only get the feasible primal and dual solution if has any, however I would like to get ...
- 173
3
votes
1
answer
71
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Jump, Julia : How to add constraints with different indexes a.c.a $x_i \leq z_j, \; \forall i, j$
I am having a constraint in the form :
$$ x_i \leq z_j, \quad \forall i, j \in \{1, 2, .., n\}$$
I know that if the right part of the equation was a constant so something like $x_i \leq c[i]$ I could ...
- 235
6
votes
1
answer
1k
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Quadratic constraints in JuMP
I am a bit new to programming and am currently working with solving optimization problems in JuMP in Julia.
I got a tip from the JuMP page that I should also use ...
- 63
5
votes
2
answers
238
views
Analyzing the output of IPOPT
I am solving a feasibility (No objective) problem in IPOPT. I got the following output:
I see that the violation of the constraints are of order 1e-15. What is the meaning of dual infeasibility 1e-07 ...
- 91
2
votes
1
answer
126
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Coding some parameters with index zero in Julia
As part of our constraints, we have
\begin{align*}
&\sum_{i=1}^{I}c_ix_i\ge y, \\
&\sum_{i=1}^{I}c_{i-1}x_i\le y,
\end{align*}
where $y\ge0,x_i\in\{0,1\}, \forall i$.
I am trying to code ...
user9659
5
votes
2
answers
771
views
Julia JuMP successive optimization
I am using Julia's JuMP package to solve a cutting-plane method. Namely, I solve a sub-problem, find the most-violated constraint in the master problem, add that to ...
- 3,796
0
votes
1
answer
66
views
Trouble implementing a line-search algorithm
I am trying to implement a simple line-search algorithm in Julia. I am new to Julia programming, so I am learning it on the go. I'd like to ask for some help, if possible, to correct an error while ...
- 203
6
votes
1
answer
262
views
Is JuMPeR good enough for Robust Optimization problem?
I'm a graduate student studying Robust Optimization (RO).
So far, I've been studied the theoretic point of RO, and now I am looking for an actual tool for solving RO problems, both for practice and ...
- 166
51
votes
15
answers
13k
views
Are Python and Julia used for optimization in industry?
I am giving a small computer exercise that aims at teaching students the basics of a modelling language to model small optimization problems. So far I have been using the modelling language GAMS as ...
- 1,658
12
votes
3
answers
288
views
Connection between solver and Julia's JuMP
I am looking for ways or tips to connect a solver with the JuMP package. I started reading the manual of Math Opt Interface — I don't know the right terms, but I'll call it the backend of JuMP. Also, ...
- 326