Questions tagged [cplex-python-api]
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31 questions
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Markowitz Portfolio : Solution differs between Lingo and Cplex
I am working on the Markowitz Quadratic Portfolio optimization.
I have this Lingo code :
...
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95
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Docplex CP Model Solution Found but Can't Retrieve Decision Variable Values
I'm using Docplex's Constraint Programming model with two 4-dimensional binary decision variables:
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- 139
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CPLEX 20.1.0.0 and python version 3.10
I am trying to develop in python 3.10, and locally I have cplex 20.1.0.0 installed. It appears to me that the python interface cplex only supports python version 3....
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Can a logical expression be added to the objective function of a model in docplex?
I'm working on an optimization problem using Docplex and wonder if it's possible to incorporate a logical expression into the objective function of my model.
Specifically, I have three variables x, y, ...
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Dual problem in IBM CPLEX
Im solving n-dimensional Knapsack problem as LP problem.
I noticed that sometimes dual LP problem may be solved much faster than primal.
My test problem contains 500k variables and 50k constraints, ...
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Updating constraint set rhs in docplex
I am trying to update the rhs of a constraint iteratively under a while loop in docplex, however, it does not work properly. As I analyze the output text file, while some constraints are updated as I ...
user5245
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Modifying and re-optimizing a model using CPLEX Python API
I came across the following functionality that is offered by CPLEX for modifying and re-optimizing a model based on previous computations: https://perso.ensta-paris.fr/~diam/ro/online/cplex/cplex1271/...
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Google-OR tools vs Pyomo and other commercial Solvers for solving a simple maximum flow problem
I have implemented a Pyomo model for solving maximum flow problem as a subroutine of an algorithm. However, the approach does not scale very well because Pyomo does not provide a very good way to re-...
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Sensitivity analysis for specific sets of constraints on DoCplex
I am working on DoCplex to run a large model with several variables and constraints. I used the following link from sensitivity analysis in python + Docplex to run the sensitivity analysis. In that ...
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Using CPLEX academic version with Pyomo on MacOS
I have recently tried to use the CPLEX solver to solve one of my Pyomo models. I first installed the community version that is available:https://pypi.org/project/cplex/ using ...
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How to do matrix multiplication in docplex in python?
Here's an applicative problem I'm trying to solve. Imagine there is a road that can be classified in 5 states. Can be something from good to bad etc. There are 4 maintenance actions possible. And the ...
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User callback doing nothing slows down Cplex
I am trying to do something with user callbacks in Cplex using Python API. For instance, I will need a callback that only counts the number of explored nodes.
While testing something I noticed that ...
- 251
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Objective value estimate for branches I create in Cplex
I' implementing custom branching heuristics for Cplex in python. I have a way to choose a (binary) variable to branch on, so use the following code to create two branches from BranchCallback (...
- 251
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235
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Getting all active constraints of an LP from Cplex
I was wondering if it is possible to get the active constraints of a linear program from the Python API of Cplex? Or do I have to go through the constraints one by one and check if they bind with ...
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