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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 free for academic purposes, 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. SCIP is free for academic research and can be licensed for commercial use.

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Solving an integer linear program: why are solvers claiming a solvable instance is infeasible?

I'm trying to solve integer programming problems. I've tried both use SCIP and LPSolve For example, given the final values of A and B, I want to solve for valA in the following C# code: Int32 a = 0, b = 0; a = a*-6 + b + 0x74FA - valA; b = b/3 + a +…
Craig Gidney
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Speed of CPLEX vs CPLEX using SCIP

I am new to LP and have only briefly used PuLP in Python. Why is there a speed difference between SCIP 3.2.1 - CPLEX 12.63 and CPLEX 12.6.3? Doesn't SCIP still use CPLEX for solving? Why will someone use SCIP with CPLEX solver, instead of using…
Nyxynyx
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How to use and build a makefile to link scip to C?

I am very new in C. I just need to use one of the functions in scip. I made a make file as below: SCIPDIR=$/Users/amin/Documents/cProgram/scipoptsuite-6.0.2/scip include $(SCIPDIR)/make/make.project %.o: %.c $(CC) $(FLAGS) $(OFLAGS)…
sherek_66
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parameterized vector with PySCIPopt

I'm attempting to use PySCIPopt to solve a traditional Ax-b + constraints type of problem. I have many values of b, and I need to run the optimizer on each of them. How can I reuse the setup? Second question, what is the equivalent of norm in…
Brannon
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Installation problems of PySCIPOpt on Windows

when I run pip install pyscipopt I get the following error: build\lib.win32-3.7\pyscipopt\scip.cp37-win32.pyd : fatal error LNK1120: 311 unresolved externals error: command 'C:\\Program Files (x86)\\Microsoft Visual…
Michael Grant Warshowsky
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SCIP Customized settings not loaded

I have defined customized settings in a file called scip.set and put in in myscipdir/settings. The settings contain limits/time = 86400 limit/memory = 61440 lp/threads = 6 However, SCIP doesn't seems to load the customized settings,…
twfx
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Use of threads in SCIP

In the list of SCIP's parameters I see three types of references to the use of threads: lp/threads (threads used for solving the LP, which don't matter when using SoPlex, according to this question). parallel/{min, max}threads (number of threads…
rocarvaj
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pyscipopt, nonlinear system of equations, code is working but slow doesn't scale

I have a system of equations to solve which goes like this: https://imgur.com/oxVdM10 the left side of the equation is the sum, and the right side is the constraints. I have a system of N nonlinear equations with N variables. I tried solving it with…
Lionel Yelibi
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Set MIP termination gap with PySCIPOpt

I cannot figure out how to set a MIP gap threshold such that the solver will terminate when the relative difference between the primal and dual solutions is within some value. I am using PySCIPOpt to interact with SCIP. I am sure there is a simple…
kenl
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error of building google or-tools on win7

I would like to install google-or-tools (https://code.google.com/p/or-tools/) on win 7 so that I can call third party optimization solvers (scip http://scip.zib.de/ ) from vidsual studio 2013. I am new to the or-tools. I followed the instructions…
user3601704
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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…
Kitserve
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Multiple MILP solutions in ORTOOLS [python]

I am trying to use or-tools in Python to solve a mixed-integer linear program that has multiple optimal solutions. However, NextSolution() always returns False, so I cannot retrieve more than one solution. I understand that this function works…
David Haley
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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…
She'ifa
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