All Questions
Tagged with cplex mixed-integer-programming
77 questions
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65
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My CPLEX Decision Variables shows "No Value"
Good day, I’m currently using the CPLEX Studio IDE v.22.1.0 for my university project and it’s my first time. I am working on “Reducing Overcrowding in an Emergency Department” by optimizing five (5) ...
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1
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47
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why it always results zero regardless of an example for optimal value
I have coded the multy commodity flow problem using MIP and CPLEX solver but for any example I provide it leads to 0 as optimal value. I believe the problem lies within either in objective function or ...
0
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1
answer
31
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How to represent a priority constraint in CPLEX Studio using OPL?
I am working on an optimization problem about the WFP where i basically have a set of countries where each contry belongs to a specific region. And each country is also represented by an Emergency ...
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0
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1
answer
185
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ProgressListener in docplex (CPLEX)
I am using docplex (CPLEX Python API) to solve a mixed integer programming model.
Let us say that I have a minimization problem, and I have a lower bound for the objective function of that problem. I ...
- 137
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2
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139
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Optimization problem in C++ does not yield the same result as in CPLEX
so far I modelled optimization problems directly in IBM ILOG CPLEX Optimization Studio.
Now, I want to try out using C++ to formulate models while using the CPLEX API.
For this purpose, I started out ...
- 141
0
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1
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56
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Reading a nested array Using SheetRead from Excel file in IBM ILOG CPLEX OPL
I am trying to read a set of players P that play in position Q from excel. A sample of how the sets look is given below -
// set of positions q
Q = {"GK", "DEF", "MID", &...
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1
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51
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Needassistance Debugging " Data element already Been set" error on IBM ILOG CPLEX studio
I have made a model to optimize FPL team selection and tried running for 3 rounds of the season. However I am getting an error for the data set "Pq" which is the set of players p allowed to ...
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1
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150
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How to convert non linear constraint to new linear constraints?
I have converted the non-linear expression [1]: https://i.sstatic.net/MzzSO.png into linear equations 11, 12 and 13. But when I run my code, I got these errors: "constraint labeling not supported ...
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0
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1
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446
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Read a solution file using Python API of CPLEX
I have a MIP and I solve the problem within a matheuristic framework, therefore I solve the problem multiple times. However, I want to save certain solutions and read the solutions from those files ...
- 13
2
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2
answers
1k
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SCIP does not find good solution for MIQP problem while CPLEX finds one very quickly
I want to solve a mixed integer quadratic programming problem with 267 variables [1] using SCIP.
CPLEX can solve the problem in about 30 seconds and a solution that is extremely close to the optimum ...
- 559
0
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1
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90
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Objective function definition for MIP using docplex
import numpy as np
rnd = np.random
rnd.seed(0)
n = 6
t = [i for i in range(1, n)]
V = [0] + [i for i in range(1, n + 1)]
o = 5
operator = [o for o in range(1, o)]
precedence = [[1, 2], [1, 3], [...
0
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1
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137
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How to run multiple instances (datasets) from same CP model in CPLEX?
I am trying to make an Iteration code by 'using CP' in cplex (12.6).
I used this script for OPL model.
What I need to change my code below to execute CP model?
main.mod
{string} datafile = ...;
int ...
- 1
0
votes
2
answers
870
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How can you load in an MPS file into CPLEX?
I wanted to use the "IBM CPLEX Optimizer Studio " to open an MPS file and solve it. I could find instructions on how the MPS file should look like, but nothing on how to actually load it in.
...
- 3
0
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2
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175
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Warning: dvar has never been used by the engine
I am trying to solve a MILP (Kasapidis et al. 2021). It contains two sets of decision variables for allocating tasks to a machine and sequencing the tasks on a machine:
dvar boolean X[operations][...
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0
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0
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48
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How to code a constaint that contains an integral in java &cplex?
I started Java programming 2 months ago. I don't know how to code a constraint in the Java+Cplex library. This constraint contains an integral. Does Java contain an integral library already and I'll ...
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