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by wenc 3035 days ago
> whereas I wanted for the solvers to all agree on some language.

Umm, they (mostly) do. Pyomo supports the AMPL .nl format, which means you can call any AMPL solver from Pyomo (most COIN-OR solvers have AMPL interfaces). The AMPL .nl format is the de facto standard for open-source optimization solvers because it's the only open standard, I believe [0].

So you would define your mathematical program in Pyomo (which isn't a terribly challenging syntax compared to AMPL). When you invoke solve, Pyomo will spit out an .nl file and call a solver (which reads the .nl file, solves the problem, and outputs a .sol file which can be read back into Pyomo).

Incidentally this is exactly how it works in AMPL as well -- all the interop is done through .nl and .sol files. I recommend reading [0] to understand how this works.

[0] https://ampl.com/resources/hooking-your-solver-to-ampl/
1 comments
xoroshiro 3035 days ago
Oh, wow. I couldn't really figure out which parts of AMPL were proprietary and I guess I immediately dismissed it after that without understanding how it worked.

As for Pyomo, while at first glance I dislike the syntax (it's not as easy to share with others, at least compared to something like GNU MathProg, where the receiver doesn't need to concern themselves with python or julia), I like python enough to maybe give it a try. I'll have to learn more about it though. Thanks to you and the others!

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