AmplNLWriter with JuMP 0.21.2

Specific Domains Optimization (Mathematical)
1

How to use Couenne (using AmplNLWriter) following the recent changes to the JuMP interface.
In particular I am trying

m = Model( () → AmplNLSolver(“couenne”) )

and I get the following error:

ERROR: LoadError: The provided optimizer_constructor returned an object of type AmplNLSolver. Expected a MathOptInterface.AbstractOptimizer.

2 
using JuMP, AmplNLWriter
m = Model(()->AmplNLWriter.Optimizer(ENV["COUENNE_PATH"]))

works for me (I have the couenne path set as an environment variable).

1 Like
3

This line no longer works for me (I had something similar working in a previous Julia / JuMP installation) - I get:

ERROR: LoadError: UndefVarError: Optimizer not defined

4

Weird, here is my installed versions of the relevant packages:

AmplNLWriter v0.6.0
JuMP v0.21.2
MathOptInterface v0.9.13
5

It is very strange indeed. Before I had AmplNLWriter 0.5.0. Now that I updated to 0.6.0 (JuMP 0.21.2, MathOptInterface 0.9.13) it I get:

ERROR: LoadError: The provided optimizer_constructor returned an object of type MathOptInterface.Utilities.UniversalFallback{AmplNLWriter.InnerModel{Float64}}. Expected a MathOptInterface.AbstractOptimizer.

My Julia version is 1.4.1

6

You need to quit Julia and restart to load the new version of the package.

2 Likes
7

Thank you both. It worked after restarting…

1 Like
8

I have the same issue. I have tried both m = Model( () → AmplNLSolver(“couenne”) ) and m = Model( () → AmplNLWriter.Optimizer(“couenne”) ) but I get

ERROR: The provided optimizer_constructor returned an object of type AmplNLSolver. Expected a MathOptInterface.AbstractOptimizer.

ERROR: UndefVarError: Optimizer not defined

I have the latest version of Julia and all the package are updated.

Thanks very much for your help.

9

all the package are updated.

Unfortunately, it looks like they aren’t. You need AmplNLWriter v0.6.0: Release v0.6.0 · jump-dev/AmplNLWriter.jl · GitHub

Run the following, then report the output:

import Pkg
Pkg.status()
] add AmplNLWriter@0.6
10

Status ~/.julia/environments/v1.4/Project.toml

[7c4d4715] AmplNLWriter v0.4.2
[2f02e5f0] CouenneNL v0.0.0 #master (https://github.com/rdeits/CouenneNL.jl)
[60bf3e95] GLPK v0.13.0
[4076af6c] JuMP v0.21.2

(@v1.4) pkg> add AmplNLWriter@0.6

Updating registry at ~/.julia/registries/General
Updating git-repo https://github.com/JuliaRegistries/General.git
Resolving package versions…

ERROR: Unsatisfiable requirements detected for package AmplNLWriter [7c4d4715]:
AmplNLWriter [7c4d4715] log:
├─possible versions are: [0.4.2, 0.5.0, 0.6.0] or uninstalled
├─restricted to versions 0.4 by CouenneNL [2f02e5f0], leaving only versions 0.4.2
│ └─CouenneNL [2f02e5f0] log:
│ ├─possible versions are: 0.0.0 or uninstalled
│ └─CouenneNL [2f02e5f0] is fixed to version 0.0.0
└─restricted to versions 0.6 by an explicit requirement — no versions left

11

You cannot use CouenneNL with the latest version of AMPLNLwriter.

You can download the Couenne binary directly from here: Open Source Solvers - AMPLAMPL

12

Thanks. I have downloaded couenne. but I have still ERROR: LoadError: UndefVarError: Optimizer not defined when I use global model = Model(() → AmplNLWriter.Optimizer(“./couenne”))

13

You need to remove CouenneNL, then update:

] rm CouenneNL
] up

Then you need to exit Julia, and restart a new session to load the fresh code.

14

Now it works perfectly. Thanks so much.