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Questions tagged [scip]

Software package for solving mixed integer linear and nonlinear programming problems and part of the SCIP Optimization Suite. SCIP is distributed under the Apache 2.0 license and its C source code is available.

Mixed integer programming is the task to optimize a linear functional over a polyhedron, where some or all variables are constrained to be integer. The SCIP Optimization suite offers a branch-and-cut implementation, and a standalone implementation of the Simplex algorithm, called SoPlex, to solve linear programming problems.

Furthermore, SCIP comes with a modelling language ZIMPL that aims to ease the task of formulating mixed integer programming problems, a parallel solver called UG, and an implementation of the branch-and-cut-and-price algorithm called GCG.

The SCIP Optimization suite is one of the fastest implementations whose source code is available. It is written in C, but also offers a C++ interface.

<= 03.11.2022:
  • SCIP is free for academic research and can be licensed for commercial use.
>= 04.11.2022:
  • SCIP (as well as SoPlex) is distributed under the Apache 2.0 license.
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Is it possible to convert a MathProg MIP file to a format recognised by SCIP?

I've been using GLPK to solve some mixed integer programming problems. Here's a sample input file in MathProg format: set REACTIONS; set REACTANTS; param Ys {i in REACTANTS, j in REACTIONS}; param Gamma {i in REACTANTS, j in REACTIONS}; param…
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Obtain best feasible solution with SCIP

I am using SCIP (SoPlex) to solve a MIP (mixed integer program) provided by a .mps file. I use SCIP via command line as follows: SCIP> read file.mps original problem has 1049 variables (471 bin, 0 int, 0 impl, 578 cont) and 638 constraints SCIP>…
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How to solve integer optimization problem with Python?

I have a system of linear equations Ax=b, A - matrix (m x n), x - (n x 1), b - (m x 1). The matrix A is almost all 0 and contains only ~ n*m^(1/2) non-zero elements. m and n can be quite large, such as n=28680, m=22500 or n=28680, m=62500. It is…
Alex
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Is the SCIP solver multi-threaded in PULP?

When I run the cord below at Jupyter-notebook, solver = SCIP_CMD(path=scip_file, threads =7) it returns the following error. SCIP_CMD.__init__() got an unexpected keyword argument 'threads' I checked the git-hub code but I could not find the…
Takeshi Matsuda
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How to get pyscipopt running on macOS

I am trying to install pyscipopt from the SCIP Optimization Suite in order to use SCIP solver in Python. I already downloaded SCIP Optimization Suite from the SCIP Website. Unfortunately, my mac terminal returns an error when trying: "pip install…
LukPau
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SCIP/OR-Tools: Stop solver after certain objective value has been reached

I am using or-tools with a SCIP to solve some Mixed Integer Linear Program. In other solvers, I know there are options to stop the solver once a certain objective value has been reached, for example the BestObjStop option in GUROBI. Is there a…
cryptobeginner
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How to get relative MIP gap in Google OR-Tools and Python via SCIP solver?

When cancelling a solution search early, which is not based on a specified rel. MIP gap limit but e.g. via a time limit, is it possible to display the relative MIP gap of the best feasible solution that was found by the solver?
sixflags
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Slight difference in objective function of linear programming makes program extremely slow

I am using Google's OR Tool SCIP (Solving Constraint Integer Programs) solver to solve a Mixed integer programming problem using Python. The problem is a variant of the standard scheduling problem, where there are constraints limiting that each…
easox
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SCIP 7.0.3 installing using cmake on macOS TBB error

I am trying to build the SCIP 7.0.3 opt suite on my Mac machine and I facing some issues. I am using CMake to generate the make Makefile and once I type make, I am failing at the linking step. I am attaching the log here Consolidate compiler…
Morpheus
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Generalized Traveling Salesman Problem in zimpl

I am new to zimpl and I am currently trying to modell the GTSP. The setting is that we have nodes which are grouped into clusters. My problem is i dont know how to implement in zimpl which node belongs to which cluster. What I did so far: set V:=…
gtspquestions
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facility location with OR-tools

i'm trying to write facility location MIP solution with OR tools. i translated a Scip solution, from here: https://scipbook.readthedocs.io/en/latest/flp.html but im getting a table with only zeros means a no solution.. is the framing of the problem…
Asael Bar Ilan
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Google OR-Tools (using SCIP solver) - How to access the intermediate solutions found by the solver?

I'm new to Google OR-Tools. Using Python, I implemented a MIP model with SCIP as a solver. The objective function is for minimization (solver.Minimize(C)) and I am accessing the final solution through solver.Objective().Value(). However, I also need…
lbrandao
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How to configure VSCode to work with SCIP Optimization software

I am trying to move to VSCode from sublime text and I was wondering how to configure VSCode to work properly with SCIP. my c_cpp_properties.json file looks like this: { "configurations": [ { "name": "Mac", …
Morpheus
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Problem when importing PySCIPOpt. AttributeError: type object 'pyscipopt.scip.Expr' has no attribute '__div__'

I want to use python interface for SCIP; I installed PySCIPOpt following these steps. I'm using SCIP7, PySCIPOpt 3, and python 3.7. SCIP's interactive shell alone works well. However, when I try to import pyscipopt, I get the following error File…
Sana ik
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Using SCIP as the solver for Pyomo

I'm a total novice at adding solvers to Pyomo that don't just have a conda or pip install like gurobi. I'm trying to install SCIP and interface it with Pyomo. I have the scipampl-6.0.0.win.x86_64.intel.opt.spx2.exe and I'm wondering where to put it…
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