All Questions
Tagged with cplex linear-programming
262 questions
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Docplex use for timeseries based variables
I am trying to model an optimisation problem where each item in a list is essentially power generated at that hour. I am trying to minimise the amount of energy stored while still getting the same ...
- 23
0
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1
answer
29
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Reduced Costs in IBM ILOG CPLEX Optimization Studio
In this Stack Overflow post, they give the code to find the solution duals (shadow prices).
execute
{
writeln(ctMaxTotal.dual);
writeln(ctMaxTotal2.dual);
writeln(ctMaxChloride.dual);
}
What is the ...
0
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1
answer
50
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How to solve an infeasible column error in a linear optimization problem?
While trying to solve a linear optimization problem (say Scenario A) with CPLEX, I am getting
Infeasible Column ys.IM...G....044 error as shown below:
[![enter image description here][1]][1]
The ...
- 1,730
0
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0
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44
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Use exported sav to run barrier+crossover got different result
I have a large pure LP model and written by c# API. In c# API, we build the model and solve it with the following settings,
2024-09-19 12:03:42.608 +08:00 [INF] Version identifier: 20.1.0.0 | 2020-11-...
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1
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72
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How to access best LP node solution in branch and bound tree in CPLEX?
I am running a MIP for a finite time and it terminates with a non-zero gap. I want to access the solution (the decision variables and the objective) of the best LP relaxation (best lower bound for a ...
- 1
0
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1
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72
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Modelling Multi period multi product aggregate production planning problem in cplex
This is the model that I am trying to input into cplex
Model
These are the description which describe the model above
Sets:
P: set of all products
K: set of all work centres
L: set of all operations
L(...
0
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1
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137
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Using the piecewise function in the objective function of the IBM CPLEX python API
I can't find the piecewise attributes when using Cplex in Python.
I know with docplex this can be done for example:
from docplex.mp.model import Model
mdl = Model(name='')
f=mdl.piecewise()
Is ...
0
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1
answer
72
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How do I implement this model in CPLEX?
I am new to CPLEX. How to write the code for this:
I have tried few ways but none seemed to work. I couldn't figure out how to code, I looked at many examples but I couldn't find anything similar to ...
- 11
0
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1
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115
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How to code nonlinear constraints in CPlex opl?
This is a part of my Cplex code. I want to code the constraint below but it seems nonlinear constraints and can not run in CPlex opl. Can anyone help me deal with it?
Here is the constraint
...
int ...
-1
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1
answer
47
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Clustering problem constraint error CPLEX cannot extract expression
I've written following code for a clustering problem:
range N=1..10;
range M=1..2;
float distance[N,N]=...;
dvar boolean x[M,N];
dvar float+ Z;
minimize Z;
subject to {
forall(i in N, j in N,...
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0
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0
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69
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How to define this complex labor rule as a constraint in MIP?
Im trying to define a complex labor rule as constraints in a MIP, solved with CPLEX.
My key decision variable is a binary x(i,j) indicating if shift i is assigned to employee j.
The labor rule is as ...
1
vote
1
answer
58
views
How to write the constraint (A + B <= 1) in DOcplex?
I am new to DOcplex. I have two binary decision variables A and B and I wish to write the constraint (A+B <=1). I tried to write the constraint using "+" operator but it does not work.
...
- 13
0
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1
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132
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Exception from IBM ILOG concert: can not read data from excel
I am using IBM Cplex studio IDE to solve an optimization problem called location set covering problem with backup, I have coded the model and solved it for a small problem, which works fine. When I am ...
0
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1
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112
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Piecewize Python CPlex
This is my optimization problem :
My company sells 2 items A and B, res 20$ and 30$.
If the production of A > 0, then the cost of maintenance is 20
If the production of A > 200, then the cost ...
- 347
0
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1
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177
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How can I get the Relative/Absolute GAP from LP solution in Python with CPLEX Solver?
I'm solving a problem with PuLP in python and i'm trying to print the gap with solution.MIP.get_mip_relative_gap() but it doesn't work.
Is there a way to get this information?
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