420 questions
- Bountied 0
- Unanswered
- Frequent
- Score
- Trending
- Week
- Month
- Unanswered (my tags)
1
vote
1
answer
46
views
Manually controlling the iterations of optmize() function from pyscipopt
Is it possible to manually control the solving process of pyscipopt? I would like to repeatedly stop and resume the solving loop in a programmatic way.
This is what I've come up with so far:
m = Model(...
1
vote
1
answer
31
views
How can I access the entropy expression handler in the SCIP program?
According to the SCIP Optimization Suite 8.0 manual, SCIP contains an expression handler for the entropy function. I want to use it for the objective of my optimization program, but I don't understand ...
0
votes
1
answer
149
views
Unable to get dual values from SCIP solver
I have an LP that I am solving with SCIP. I have disabled all presolve settings (as far as I know) as I need the dual value of each constraint. However, when I use model.getDualsolLinear(i) to obtain ...
0
votes
0
answers
50
views
Using variables in forall and sum in Zimpl
I have the following ZIMPL code:
subto Restriction:
forall <a> in A:
sum <b> in B: parameter[b, a] <= 1;
When running SCIP, the result is infeasible. But if I add the b ...
2
votes
0
answers
60
views
Disabled Constraints in Branch-and-Price using SCIP
I am reaching out regarding an issue I’ve encountered in my branch-and-price implementation in SCIP. My implementation is based on the bin packing project, and I have made minimal modifications as my ...
0
votes
1
answer
177
views
Using Google OR-Tools with SCIP solver in x86 solution
I made a proof-of-concept application using Google OR-Tools with SCIP solver and it worked perfectly for my problem. But when I added OR-Tools to my actual solution (which uses .NET Framework 4.6.2), ...
1
vote
0
answers
41
views
Branching control in SCIP via Pyomo
I'm working on a "hard" scheduling problem that is currently written in Pyomo, and I'm using SCIP as the solver.
Since I know the structure of the problem, I understand that branching on ...
0
votes
0
answers
65
views
SCIP-SDP for solving mixed integer semidefinite programs
I have been looking at SCIP, specifically SCIP-SDP for solving a mixed semidefinite program - however I can't seem to find any examples on how I implement it in Python with PySCIPOpt.
Does anyone know ...
0
votes
1
answer
162
views
Obtain top N solutions in MIP problem using SCIP through OR-Tools
I would like to obtain more than one solution with SCIP. Using SAT (cp_model.CpModel()) I can collect all the possible solutions, but when they are too many, it takes way too long. I would like to be ...
2
votes
0
answers
119
views
Constraint Transformation in SCIP
I am using pyscipopt 4.3.0 (python 3.11.5; SCIP 9.0.0) to solve the following binary linear problem:
import pyscipopt as scip
_Name = "tiny_test"
m = scip.Model(_Name)
y1 = m.addVar(name=&...
1
vote
0
answers
68
views
issues with template <> during scip installation
I am trying to install scipoptsuite v6.0.1 (https://scipopt.org/download.php?fname=scipoptsuite-6.0.1.tgz) on my Mac M1. Following the instruction in the website:
Link to the changesoplex.cpp file: ...
0
votes
1
answer
255
views
ortools SCIP stuck in presolve
I'm using ortools to solve a Mixed-integer-problem, using SCIP as the solver.
And the solver.EnableOutput() is preformed, and the following output is displayed on my screen↓
(round 236, fast) ...
0
votes
2
answers
86
views
How to track the value of target function during ortools mixed-integer-programming solving process?
I'm using ortools SCIP to solve a really large mixed-integer-programming problem.
solver = pywraplp.Solver_CreateSolver('SCIP')
"""
Problem Definition Is Omitted Here
"""...
0
votes
0
answers
74
views
Exact tightened bounds in SCIP presolve?
In my current project, I want to make use of SCIP/PySCIPOpt to tighten the bounds of my system's variables given a number of constraints. However, it seems that the variable bounds after pre-computing ...
0
votes
3
answers
307
views
SCIP - stuck in clique table clean up
I'm running a multi year optimization with continuous and binary variables. For the 1st year, SCIP is able to pre-solve in 5 seconds and fully solve in under a minute, however, for the second year, ...