COIN-OR (Computational Infrastructure for Operations Research) is a collection of Open Source software for modelling and optimization in the Operations Research community
Questions tagged [coin-or]
22 questions
6
votes
1 answer
How you enable CBC to return best solution when timelimit? (Pyomo)
I am trying to use CBC(v2.10.3) on Pyomo to solve for a integer linear problem.
When executing the solver, I am currently setting a timelimit of 600s.
opt = SolverFactory ("cbc")
opt.options['seconds'] =600
Within this timelimit, solver manages to…
tb_
- 61
- 1
- 3
3
votes
1 answer
Initialize integer variables in CyLP
I'm currently using CyLP package in Python for mixed-integer linear programming. However, I'm not able to initialize integer variables. According to the documentation, I have passed isInt = True to addVariable method but it does nothing.
A minimal…
Quan Hoang
- 93
- 7
3
votes
1 answer
using Bonmin Counne and Ipopt for NLP
I want to just be sure that I am eligible to use Bonmin and Couenne for solving just the NLP problem (Still I do not have integer variable) and I am eager to obtain global optimum not local. I also read that Ipopt first search for the global answer…
Shahrokh Paravarzar
- 33
- 6
2
votes
0 answers
Install IPOPT locally into C++ codebase with CMake ExternalProject
I would like to use Ipopt in a CMake-based project using ExternalProject. The library should be installed locally and automatically in the build folder so that the user must not go through any hassle.
I can do this for simple enough repositories…
fdev
- 127
- 12
2
votes
1 answer
Optimization integer programming with covariance matrix
I am trying to do a optimization problem which requires the calculation of a new covariance matrix affected by the variable within the implementation.
I am able to do so with scipy optimization Minimize using numpy.cov within my objective function.…
Wee Darren
- 21
- 1
2
votes
0 answers
How to fix Import Error of CyLP on M1 Mac?
I want to use the CyLP package (https://github.com/coin-or/CyLP).
My OS is macOS Big Sur 11.5.1. I am using Python 3.8.8 via anaconda3.
Following the instructions in the README, I first installed cbc via homebrew. As it did not function with brew…
PhQC
- 21
- 2
1
vote
0 answers
How to let the Coin-or Cbc Solver write solution file?
I use the C++ library of COIN-OR Cbc Solver to solve some LP problems. And I can't find anywhere a function or something that writes the solution file. I think somewhere in the code there is this functionality because you can use COIN-OR's command…
Pureve G
- 11
- 1
1
vote
2 answers
Julia JuMP Cbc solver hangs infinitely without message and without exiting
I'm using Julia language (Version 1.3.1), JuMP package (Version 0.20.1) and Cbc package (Version 0.6.6) to solve an optimization problem in a docker container with ubuntu:16.04. The optimizer Cbc seems to be hung, with 100% cpu usage, without…
RobIris
- 21
- 2
1
vote
0 answers
how can i change the lower bound using JuMP 0.19
I have a variable x where its lower bound was defined as lb=zeros(3), after that I want to change for each element of lb to be equal element of an array like c=[1;2;1] what I want exactly is to make lb[i]=c[i] for i=1:length(c) I used to do this in…
Marouane1994
- 534
- 3
- 11
1
vote
0 answers
Where do I find the solver error code definitions for Coin-OR CBC that Pyomo returns?
I see ERROR: - Solver (cbc) returned non-zero return code (-9) when running my Pyomo problem.
I have tried solve(instance, tee=True, keepfiles=True, logfile="my.log") but the my.log is not appearing. I have searched through the Pyomo and cbc github…
jonas
- 21
- 1
1
vote
0 answers
Can't include Coin-or Rehearse Library to my own code
I download the Coin-or Rehearse Library, and I follow the steps present in the tutorial.
I successfully "make install" and "make test", which both seem like providing the right output.
But now I want to include this solver into my own code, which…
Tim Lee
- 11
- 1
1
vote
1 answer
"Solver did not exit normally" - Jupyter / Python3 / Ubuntu
I am trying to get my first Pyomo model running on my Ubuntu VM (Azure). I have Python3 and the COIN-OR solvers installed on this machine. No matter what solver I try, I get the same result.
Edit: changing the solver to couenne (it's a nonlinear…
Ralph
- 255
- 2
- 18
1
vote
1 answer
Pyomo - Location of Log Files
Pretty basic question, but where can I find solver log files from Pyomo? I have a local installation of the COIN-OR solvers on an Ubuntu machine.
This is happening in a Jupyter notebook, but I'm getting the same error message when I run the .py…
Ralph
- 255
- 2
- 18
1
vote
1 answer
Pyomo: is possible to assign to a design variable only defined values?
I want that a design variable assumes only specified values during optimization process.
For example:
Let x be the variable which can assume only specific value, e.g.:
x = [0.1,0.5,1.0,1.7,2.3]
How can be written in python using pyomo (if it's…
0
votes
0 answers
VSCODE with jupyter notebook: output of externally executed programs (like coin-or/pulp) are not shown in output or terminal
If I run test1.py (copied from https://github.com/coin-or/pulp/blob/master/examples/test1.py) then I get some information directly form the solver (GLPK) as output in the terminal.
If I copy the script into a notebook file, then this output is not…
JBoe
- 1
- 1
- 1