Hacker News Reader

Comment by Chio | Hacker News Reader

I can't share pricing details since they are confidential but if you just want to play with MIP you don't need to buy one of the big three (XPRESS, Gurobi, CPLEX) which are all very expensive but usually available for free for students. There are at least two good open source / free for non-commercial use MIP solvers available:

https://highs.dev/ https://www.scipopt.org/

View on HN

How do those stack up against lp_solve (https://lpsolve.sourceforge.net/5.5/index.htm)?

Waaaaay faster.

I've used both. They are waaaaaaaaaay faster, waaaay more reliable, and actually have support. You're not going to want to run your product that is responsible for millions off of something without really solid support.

Check out the Mittelmann benchmarks: https://plato.asu.edu/bench.html

You can get a temporary free license for Gurobi. You are limited to a 1000 node problem size, but you can learn how to use the tool and set up your problem.

If you have a problem that needs Gurobi, it’s worth paying for it. Talk with their sales team. They are happy to help you get started. They know once you know how to use it, and how it can solve problems you will be inclined to use it in the future.

> If you have a problem that needs Gurobi, it’s worth paying for it.

Thit statement is baed on the assumption that it is a "big money" problem. On the other hand, I know lots of problems interesting to nerds for which Gurobi would help (but nerds don't have the money).

If you have a "nerdy" problem you can probably get someone to write it up as a research paper and then it would easily fall under the academic license. To some extent, if you're buying a commercial license you're just paying for secrecy.

This is not true: to get an academic license of Gurobi, you have to be a member of a degree-granting academic institution (otherwise every person could easily (illegally) get one):

> https://www.gurobi.com/academia/academic-program-and-license...

"You must be a faculty member, student, or staff of a recognized degree-granting academic institution.

[...]

To activate your license, you must connect from a recognized academic network."

If you can't even get a random member of any degree-granting institution (could just be random research staff, a student or adjunct faculty) to take some interest in your optimization problem as a subject for publishable research, does it even qualify as a "nerdy" problem?

Plus, the setup is really fucking annoying... The number of times I had to reactivate my academic license of gurobi while in uni...

The speed is totally worth it though, literally orders of magnitude better than any alternative for wide problem classes. Plus the bindings are good enough that you rarely ever need to drop into c++

Ortools by google had good benchmarks

Other open source solvers:

- Timefold Solver (not MIP, focussed on vehicle routing, job scheduling, shift rostering, etc): http://solver.timefold.ai

- Several solvers at COIN-OR: https://www.coin-or.org/

- Choco

Their price list wasn't that confidential last I spoke with the sales team. It depends on the license type. Last I heard, it's around $15k/year for a standard subscription license. You can probably trial it for free, or be a student and have longer free access.

Reply on news.ycombinator.com