Python-MIP and solver HiGHS

[Mateus Santana]

Hi guys!

I'm trying to use the solver HiGHS while implementing my model using Pyhton-MIP, but I'm having some issues. Although I already installed e reinstalled the solver in several ways (like via pip install highspy or via source code), I keep getting this error message:

FileNotFoundError: HiGHS not found.Please install the `highspy` package, orset the `PMIP_HIGHS_LIBRARY` environment variable.

when I declare my model:

from mip import *

import highspy

highspy.Highs()

model = mip.Model(sense=MINIMIZE, solver_name='highs')

I would like to know if someone already had this issue and could help me solving it, please.

Thank you so much!

[Luciano Rigolin de Almeida]

Hi.

The error appears to be saying that the PMIP_HIGHS_LIBRARY environment variable is not set. Have you set this variable?

Att,

Luciano Rigolin

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[Mateus Santana]

Good evening, Luciano. Thank you for your reply!

I have tried different values for this environment variable. Initially, I set the variable to the same path where I installed HiGHS, following their instructions (Getting started · HiGHS Documentation). However, it didn’t work. I then tried different paths for the variable, such as the build\bin folder and its adjacent directories, but I still haven’t been able to connect the library to HiGHS.

It might be an issue with the solver itself (I also contacted their team but haven’t received a response yet). What’s strange, though, is that I didn’t encounter any similar issues when using Pyomo.

Could the problem be that I’m setting the wrong path for the variable?

[Luciano Rigolin de Almeida]

Bom dia.

Não sei mesmo. Pode ser mesmo um problema no Python-MIP. Já usei o Python-MIP com o solver Gurobi e foi com sucesso.

Já com o HiGHS, nunca usei, nem sabia que dava.

=================================================

Good morning.

I really don't know. It could be a problem with Python-MIP. I've used Python-MIP with the Gurobi solver before and it was successful.

I've never used HiGHS, and I didn't even know it worked.

To view this discussion visit https://groups.google.com/d/msgid/python-mip/d0af76a5-ffe7-4490-89ac-cba4d748e931n%40googlegroups.com.

[Torschtl]

According to the project's website https://www.python-mip.com/ only two solvers are supported (at the moment) CBC and Gurobi:

Multi-solver

Currently integrated with the C libraries of COIN-OR CBC solver and the commercial solver Gurobi. Other solvers will be supported soon.

Based on what source do you expect that HiGHS could be used too? 

[Douglas Mazzinghy]

https://github.com/coin-or/python-mip/blob/master/mip/highs.py

To view this discussion visit https://groups.google.com/d/msgid/python-mip/ed2999c1-0548-4ad0-9eea-d34d44bd50a8n%40googlegroups.com.

[Torschtl]

Thank you, that's very useful to know 👍