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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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Division Objective function in Pyscipopt

I am trying to maximize the division of two quantities in PySCIPOpt. Since it is a division of two linear metrics, it becomes a nonlinear optimization. My code is somewhat like this: model = Model() x={} for i in range(0,len(data)): x[i] =…
linearprogrammer
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how to start SCIP in Windows 7 when I want to use GCG

I want to use GCG's branch-and-price frame to solve a MIP which is similar to Binpacking problem. So I download the SCIPOptSuite-6.0.0-win64-VS15.exe and install it in Windows 7 and then install the Visual C++ Redistributable Packages which is…
Qidong
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Using ParaSCIP (UG) in PySCIPOpt

I was wondering how to install and use ParaSCIP (UG) in python for SCIP Optimizer. I've looked through available information and haven't seen any information if UG is implemented in PySCIPOpt. Also default win distribution of SCIP Optimization Suite…
Johnny Cheesecutter
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SCIP: how to compare objective values of two SCIP_SOLs?

Is there a function that can compare two SCIP_SOLs and determine whether one SCIP_SOL is more optimal than the other? I am hoping to use this in a branching rule using the solutions in the solution pool.
Kelvin Davis
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SCIP what is the function for sign?

I am new to SCIP and have read through some of the example problems and documentation, but am still unsure how to formulate the following problem for the SCIP solver: argmax(w) sum(sign(Aw) == sign(b)) where A is a nxm matrix, w is a mx1 vector, and…
tamtam
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SCIP error: LU pivot element is almost zero (< 1e-10) - Basis is numerically singular

The scip always running and report the error: LU pivot element is almost zero (< 1e-10) - Basis is numerically singular, Could anyone tell me how to solve this question? Update SCIP version: 6.0 What's solver? I use the default solver by using…
Kisme
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I got segmentation fault\changing feastol dafault value

I have a SCIP project to solve a binary problem with nonlinear objective function that works well but for some instances I got a message saying "the best solution is not feasible", and there is some violation in the constraints. (The violation is…
pira pira
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SMPS files that are not read by SCIP 6.0

I have a set of SMPS files that are read by Coin-SMI's SMPS reader, but not by SCIP 6.0's. Actually, SCIP 6.0 shows ''Segmentation fault (core dumped)'' when it tries to read .sto file. Could you take a quick look at it please to see which part is…
Yongkyu Cho
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Getting SCIP Optimization to work on Azure App Service with PySCIPOpt

Question: Given the information below, is this an issue with the installation of PySCIPOpt on Azure? Or issue with the installation of SCIP Optimization Suite on Azure? Is this actually an issue with 32 vs 64? Or are there other unknowns here that…
yu guan
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use ug with soplex to solve LP problems

I think the ug use scip to solve ILP problems. But I want to solve LP problems with ug and can not find the parameters to configure ug to solve with soplex. Is it possible to do so, or the LP solver is scalable enough and does not the trouble?
vondart
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scip numeric issues larger than e-06

I'm using SCIP with Python (via Jupyter Notebook) and solve an ILP. When I change the input numbers it is possible that the result values of the integer variables are not integer anymore. I've seen in a post…
stahldonnerklinge
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PySCIPOpt/SCIP - isLPSolBasic() not in pyscipopt.scip.Model

I developed a gomory cut for a LP problem (based on 'test-gomory.py' test file) which I could not manage to run. Finally, I copied the test file to check whether I'd the same trouble. Indeed I got the same message: if not…
PC_AD
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SCIP - Integral separation

I developed a SCIP/MIP model using LP relaxation which relies on branching on 0-1 variables. However, it is quite inefficient as I have not figured out how to use relevant SCIP callbacks. Here is my code: isMIP = False while True: …
PC_AD
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How to precompile SCIP for visual stdio

Sorry for my poor English, I am kind of being new to the SCIP. I precompile the SCIP with minGW as http://scip.zib.de said. But when I want to link SCIP to visual stdio,there's only .a without .lib or .dll that I can use. I want to know how to…
Xiaoyuan Bai
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Integrating functions from other source codes in SCIP

I'm a master student and I'm currently using SCIP for my thesis. The main implementation task of my thesis is to integrate a meta-heuristic already coded in C++ and ready to be used in the SCIP branch-and-bound process to enhance the solution…
André Serrano
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