UndefVarError: solver not defined

[Meilame_Tayebjee]

Hi,

I am trying to run that small code that comes from Introduction to Julia

using JuMP, Clp
m = Model()
@variable(m, x >=0)
@variable(m, y >=0)
@objective(m, Min, 10x + 26y)
@constraint(m, const1, 11x + 3y >= 21)
@constraint(m, const2, 6x + 20y >= 39)
status = solver(m)
println("Status = $status")
println("Optimal Objective Function value: ", getobjectivevalue(m))
println("Optimal Solutions:")
println("x = ", getvalue(x))
println("y = ", getvalue(y))

Hower I get that error :

ERROR: UndefVarError: solver not defined

I tried to put :

m = Model(solver = ClpSolver())

but then I got the error:

UndefVarError: ClpSolver not defined

The versions installed are as follow:

  [e2554f3b] Clp v1.0.2
  [2e9cd046] Gurobi v1.0.0
  [4076af6c] JuMP v1.10.0

Thanks a lot for your help !

[hendri54]

It’s solve instead of solver

[odow]

That documentation is unofficial and refers to a very old version of JuMP. You shouldn’t refer to it.

Use the official documentation instead. Here’s a tutorial to get started:

Getting started with JuMP · JuMP

The proper syntax for your example is

using JuMP, Clp
m = Model(Clp.Optimizer)
@variable(m, x >= 0)
@variable(m, y >= 0)
@objective(m, Min, 10x + 26y)
@constraint(m, const1, 11x + 3y >= 21)
@constraint(m, const2, 6x + 20y >= 39)
optimize!(m)
status = termination_status(m)
println("Status = $status")
println("Optimal Objective Function value: ", objective_value(m))
println("Optimal Solutions:")
println("x = ", value(x))
println("y = ", value(y))

[Meilame_Tayebjee]

Thanks for your answer. But when running, Julia crashes . Would you know why ?

EDIT : Very briefly before crashing, this error appears.

EDIT 2 : I tried with GLPK optimizer, and it works. There seems to be an issue with Clp, could you help me understand that ?