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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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How can I store the results into a text file?

I'm solving a VRP with SCIP and I wish to export the results of the optimization into a text file. I use the following code but fails when calls the SCIPwriteBestSol function. FILE* file; file = fopen("Solution.sol",…
DHerl
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How to verify SCIP compiled with Ipopt?

I am using SCIP via Julia (currently with SCIP.jl, previous with AmplNLWriter.jl). I compiled SCIP as follows per the instructions for SCIP.jl: make SHARE=true GMP=false IPOPT=true READLINE=false ZLIB=false scipoptlib I am able to call SCIP from…
Alex D
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Installing error for SCIP in Python

I am using python 3 on windows 7 and trying to get SCIP on it. Please see the image. I want to run a mixed integer program. SCIP Any further instructions will be helpful. I downloaded SCIP 3.2.1 as seen in the image, but then I don't understand how…
Ted111
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How to install SCIP into Spyder (Python 3.6)

Can someone please tell me how to install SCIP module into Spyder (Python 3.6). This is linked to anaconda by the way. I have been trying to get this module into this python 3.6 for last two days, and I am not getting anywhere. It is frustrating. I…
DD1
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The Java interface doesn't consider all constraints

I've successfully generated the scip Java interface. During testing face, I've encountered this problem: the Java interface returns immediately a so called optimal solution (problem is solved [optimal solution found]), but some of the constraints…
LaChaleau
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Branching mechanism in B&P using SCIP

I'm implementing a branch and price algorithm in c using SCIP. Question: To call the branching mechanism, I use the basic BRANCHEXECLP mechanism. How does SCIP know when to branch? When the current relaxation solution has non-integer solutions,…
Rob Curry
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interface java and scip - not generating the right classes

I followed the steps described in the README in scip/interfaces/jni and when I get to step 6: make, it compiles all right untill I get this error: In file included from src/JniScipLibraryLoader.c:25:0: src/JniScipLibraryLoader.h:2:17: fatal…
LaChaleau
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SCIP solver JNI: how to set the memory?

So I'm using SCIP-JNI in my scala project. SCIP's JNI-based libearies make calls to binary C-based solver to do the optimizatin. Is there a way to set the memory for the solver?
Daniel
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SCIP using old code

I am kind of new to the SCIP. I want to use SCIP as a branch and price framework. I have coded the problem in C++ already and also have implemented the pricer or column generation as a function. In fact I have implemented the BP algorithm for the…
math2014
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Solve warning - Setting rounding mode not available

I compiled FiberSCIP using Cygwin with ZLIB and ZIMPL and just tested the example problem (ug_folder)/check/instances/MINLP/ex1266.mps, but I get many times the same error before solving, wich are: [src/scip/intervalarith.c:192] ERROR: setting…
herculanodavi
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Is it possible to use UG on Windows?

Is it possible to use the UG framework as an external library on Windows? I'd guess that ug[SCIP,Pthreads] would not be possible on Windows, but maybe ug[SCIP,MPI]? I checked the ug readme and the articles for ParaSCIP and FiberSCIP, but did not get…
herculanodavi
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Linear minimization program with ZIMPL

I am trying to make a linear minimization program with ZIMPL. In principle, I must have a minimum number of configurations for each class. Knowing that I have six classes, don't I normally have to get 6 results as output? But when I do it makes me…
t.so
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SCIP makefile for c++

I am beginner in using SCIP. I want to solve a simple MILP written in C++. I developed a simple makefile to compile and run my model but I realized there many nested header files when you call SCIP. I was wondering there might be a sample makefile…
Kaveh
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How to define a selected number of variables from a two-dimensional set in Zimpl?

I have an index set A and another set dim, and I need to define variables x[i,j] where i is in A and j starts from one and is <= dim[A] for each member of A: set A := { 11 .. 20}; dim := {<11>1, <12>3, <13>1, <14>1, <15>5, <16>1, <17>2, <18>1,…
Pooya
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Any recommend procedures to improve LP robustness with SCIP?

Background: I am solving a non-convex MINLP with SCIP. It contains about 100 binary variables, 8000 constraints and 8000 variables. I am initializing the problem with a heuristic based on "engineering insight". The initial point is feasible and…
Alex D
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