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10 votes

Problem is infeasible with Gurobi, feasible with cbc (but can't access objective value)

If I read the lp file and try solving with CPLEX: So I think your assumption is correct: the bug comes from CBC, as CPLEX and GUROBI both return infeasible. The CPLEX log also tells you which row is ...
Kuifje's user avatar
  • 13.5k
7 votes
Accepted

Which solvers should I use to solve large, but extremely sparse LP problems with 100-500 thousand variables?

One of the best-performing free LP solvers exploiting sparsity is HiGHS (https://github.com/ERGO-Code/HiGHS). It allows passing a starting point. For comparing relative performance of a number of LP ...
Michael Feldmeier's user avatar
6 votes
Accepted

How do I turn off preprocessing in pulp?

You can use presolve parameter and can pass it to solver(CBC) using following statement (model is your problem object) ...
anjikum's user avatar
  • 984
6 votes
Accepted

Using CBC CLI Arguments in Pyomo

You can use opt.options['Solver parameter to change']='value'. The following is part of the code that I tried and the generated output: ...
Oguz Toragay's user avatar
  • 8,667
5 votes

Which solvers should I use to solve large, but extremely sparse LP problems with 100-500 thousand variables?

Based on the Mittelmann benchmarks, I would agree that HiGHS is a contender, as is Clp (which is faster than HiGHS on some test problems, slower on others). You might also want to look at SCIP, which ...
prubin's user avatar
  • 39.4k
4 votes

CBC stalling after approximately 10 seconds

CBC does have its fair share of bugs, especially when it comes to proper termination. If you are running in multithreaded mode try running in serial (or vice-versa), and see if that helps. If you are ...
Nikos Kazazakis's user avatar
4 votes
Accepted

Best way to solve an allocation problem

I can think of a couple of ways to reduce the size of the problem, at the risk of producing suboptimal solutions. One, as Daniel Junglas suggested, it to set a nonzero threshold for affinity level, ...
prubin's user avatar
  • 39.4k
3 votes
Accepted

How to save log file from pulp , log including algorithms used by the solver?

You can use the logPath argument: prob.solve(pulp.PULP_CBC_CMD(msg=1,logPath="info.log") More information can be found here: https://coin-or.github.io/...
PeterD's user avatar
  • 1,666
2 votes

Pyomo.solvers on anaconda mac Ventura 13.0.1 (22A400)

The pyomo.solvers conda-forge package is no longer maintained. You can install the solvers you mentioned manually using something like: ...
Bethany Nicholson's user avatar
2 votes

Deterministic termination criteria for CBC

Use different parameter such as maximum number of nodes to be checked during branching, regardless the time of execution. Hope this helps.
Psyndrom Ventura's user avatar
1 vote
Accepted

Pyomo CBC 1.#j error

1.#J in C++ is the output obtained when printing a formatted double equal to infinity (1.#INF). See this related stackoverflow ...
tmoisan's user avatar
  • 126

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