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Pyomo is an algebraic modeling language and allows users to easily represent optimization problems at a high-level (by defining variables, constraints, objective, etc.). Pyomo then provides interfaces to a variety of optimization solvers including Gurobi and CPLEX. This allows an optimization model to be formulated once and then a user can experiment with ...


13

OR-Tools is a set of solver: A very popular Routing Library built on top of a traditional constraint programming solver An award winning CP-SAT solver that combines Constraint Programming techniques, SAT solver search and Boolean centric approach, MIP solver techniques like cuts and linear relaxation, and Large Neighborhood search A Simplex solver: GLOP A ...


10

You need to send your model to a solver. Let's discuss the "solver" part and the "send" part separately. The "solver" part: A solver is a piece of software that implements a general-purpose algorithm for solving optimization problems. Solvers implement algorithms like the simplex method, interior point methods, branch-and-bound, and branch-and-cut. Their ...


9

GAMS and AMPL are general purpose modelling languages and can he used to describe any type of nonlinear function, including some niche stuff like floor, ceil, max, etc (AMPL). I don't have experience with OPL so I can't comment on that. The purpose of these languages is twofold: They provide a solver interface for your math. Solvers typically require input ...


6

Different solvers have their own interfaces (for example Cplex studio by IBM). You can use the specific syntax for those IDE or interfaces to input your model and then use the solver to solve it. Although the logic behind them all is the same but those languages or syntaxes are usually differing from one solver to the other. If you need to solve your problem ...


5

According to the docs, IloNumArrays constructor signature is public IloNumArray(const IloEnv env, IloInt n, IloNum f0, IloNum f1, ...) which creates an array of n floating point objects for use in a model. Note that the constructor is a C-Style variadic function due to the ... parameter. Thus, you can assign your values while calling the constructor, i.e. ...


4

The syntax that you are using in your Pyomo code is correct and you should be able to access the GAMS solvers once Pyomo is able to find GAMS. As the error mentions, the GAMS command is not found in the system PATH. I would double check if the GAMS path is correctly added to the system PATH. A way of doing so is opening a command prompt (since you are using ...


3

The AMPL Solver Library (or ASL) is an open-source interface between solvers and modelling languages. As long as a solver can (i) read an .nl file and (ii) produce a .sol file, it will work out of the box with AMPL and any other modelling platform, such as Pyomo, that supports ASL. Unfortunately, many solvers do not come with an ASL interface out of the box....


2

One way to use CPLEX solver of GAMS in Pyomo (I am assuming you have a license for GAMS and CPLEX itself licensed for your GAMS, In other words, your CPLEX solver can only be used by GAMS) is that: You can use GAMS Writer in Pyomo to translate your model from Pyomo into a format that can be read by GAMS and then use GAMS to solve the model. In this link, ...


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