Questions tagged [modeling-languages]

For questions related to (algebraic) modeling languages such as AMPL and GAMS, which facilitate the process of translating an optimization model written in algebraic form to the matrices, vectors, and other data needed by general-purpose solvers.

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3 answers
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What is the purpose of libraries like Pyomo and Google OR tools?

I'm new to the OR world, and trying to learn the various tools available. I originally thought that Pyomo and Google OR tools were open source alternatives to commercial solvers like Gurobi or CPLEX. ...
Skander H.'s user avatar
  • 2,139
14 votes
1 answer
1k views

Comparison of Algebraic modelling languages and general programming languages

Some optimization software/frameworks (commercial or open-source) such as AMPL, GAMS, Cplex, ... have a specific Algebraic modelling language. Some of them have another type of programming that uses ...
A.Omidi's user avatar
  • 8,642
11 votes
3 answers
970 views

From a performance/speed perspective, does the programming language matter if the solver used is the same?

Perhaps a silly question, I know... But just wondering if the programming language has an impact here if the solver used is the same? For instance, the same model formulation being solved using Gurobi ...
epilefst's user avatar
  • 159
11 votes
1 answer
614 views

I've formulated my optimization model; now what?

I've formulated my linear/nonlinear/integer/mixed-integer optimization problem in algebraic form (possibly with the help of the folks on this site). Now what? How do I solve it?
LarrySnyder610's user avatar
10 votes
2 answers
2k views

How to get GAMS's solvers to work from Pyomo?

I want to run a model written in Pyomo language with CPLEX solver of GAMS. However I get the following error: ...
rgholizadehr's user avatar
8 votes
1 answer
1k views

Understanding the AMPL Solver LIbrary within Pyomo

For anyone familiar with the Pyomo book, it occasionally makes reference to the AMPL Solver Library, and to my understanding, if you can manage to hook up to the solver library then you are able to ...
GrayLiterature's user avatar
7 votes
0 answers
163 views

Modelers and modeling languages: how do you choose, and which features do you use?

There are many modeling languages and APIs around. One or more per solver, plus many that target multiple solvers: AMPL, GAMS, PuLP, JuMP, Pyomo... Among all these possibilities, why did you pick a ...
Ggouvine's user avatar
  • 1,867
6 votes
2 answers
318 views

Does a modeling language that generates SAT instances exist?

Nowadays, we enjoy the expressivity of modern modeling languages. However, does it exists a modeling language that takes in input a declarative problem definition (like AMPL or MiniZinc, or similar),...
Stefano Gualandi's user avatar
6 votes
1 answer
320 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 ...
Seok's user avatar
  • 166
3 votes
1 answer
517 views

How to assign values to array in CPLEX with C++?

I am new to CPLEX. I am using CPLEX with Xcode in macOS. I have three arrays (known parameters used in optimisation) which I define as ...
KGM's user avatar
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3 votes
1 answer
266 views

Solver options in Pyomo as long as using the NEOS solvers

I am working on a scheduling problem that is already coded in Pyomo. To solve the problem, I have used the NEOS solver, CPLEX. Now, to test and run some of the instances, I need to call some CPLEX ...
A.Omidi's user avatar
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2 votes
1 answer
5k views

No executable found for solver 'ipopt

I know that there are some questions concerning this type of error, for example, this link. I first installed the latest version of ipopt through command line into my Pyomo environment and got the &...
Sik Sik's user avatar
  • 133
2 votes
1 answer
47 views

Automatic Reformulation Tools For AML Programs

Are there any tools to transform programs written in an algebraic modeling language like GAMS,AMPL,... into a different formulation. E.g. there is a quadratic constraint $\sum_j b_i b_j = N, b \in \...
Lars Hadidi's user avatar
2 votes
1 answer
162 views

Using networkx predecessors in Pyomo initialize method

I am working on the directed graph by using the Networkx package and what I need is to use its predecessors' method on an optimization model. Let's say, there exists a directed graph with just $12$ ...
A.Omidi's user avatar
  • 8,642
2 votes
0 answers
66 views

Discrepancy between CPLEX interface solution and C API

I have a C API program uploaded here in Dropbox that is an LP. Here is the problem: When I compile the C file it gives me "1017 Not available for mixed-integer problems" while the problem is ...
Max's user avatar
  • 27
2 votes
0 answers
138 views

How to use NEOS without using Pyomo

I am new to modelling language and specifically NEOS server. I aim to solve MINLP using Baron, through the NEOS server. So, far I have been able to write model file, data file and command file as ...
user avatar
1 vote
1 answer
123 views

Which combinations of python modeling libraries and solvers support logarithmic objective functions?

As I understand it, if a modeling library (pyomo, amplpy, cvxpy, etc.) allows one to define a logarithmic objective function a solver may not support it. And even if a solver does support a ...
Nick Laws's user avatar
1 vote
3 answers
131 views

Optimization solver that satisfies variable values within set membership

Is there a solver that can handle an AMPL model of this sort: ...
wanderinganon's user avatar