ERROR: Solver log: Unrecognized flag or missing argument: -AMPL

[dol...@oliversystems.net]

I am trying to use gurobi 8.0 with pyomo 5.5. When solving a simple model as a test I get the following error: ERROR: Solver log: Unrecognized flag or missing argument: -AMPL

from pyomo.environ import *


model = ConcreteModel()


model.x = Var([1,2], domain=NonNegativeReals)


model.OBJ = Objective(expr = 2*model.x[1] + 3*model.x[2])


model.Constraint1 = Constraint(expr = 3*model.x[1] + 4*model.x[2] >= 1)


solver = SolverFactory("gurobi_cl")


results = solver.solve(model)  #error here


model.solutions.store_to(results)


print(results)

[Siirola, John D]

You should create the solver with:

 

                solver = SolverFactory(“gurobi”)

 

john

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[David Oliver]

I just installed gurobi (v8.0) and there Ido not see gurobi.exe file in the package.  There is a gurobi_cl.exe.  Using  solver = SolverFactory(“gurobi”) throws this error:

   WARNING: Could not locate the 'gurobi' executable, which is required for solver gurobi

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David Oliver

Oliver Systems, LLC

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[Bynum, Michael Lee]

How did you install gurobi?

Michael

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[David Oliver]

via Anaconda

[Bynum, Michael Lee]

I think Pyomo uses gurobi.sh by default. I have seen an issue before where installing gurobi with conda somehow leaves out gurobi.sh, but importing gurobipy within the active python works fine. Can you briefly try 

Solver = SolverFactory(‘gurobi_direct’)

Michael

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[David Oliver]

Will do and then report.

[David Oliver]

Michael,

Using  gurobi_direct’works!  Am I getting the full feature set of gurobi with that call, or should I work on my installation until I can get  Solver = SolverFactory(‘gurobi’) working.  Also, do you have any recommendations for documentation/tutorials/sample code that a newcomer should know about?

Thanks,

Davied