Questions tagged [linear-optimization]
38 questions
0
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1 answer
Is there a way to have a formula or script pick an amount of pre-set lengths to cover an area
Apologies if the title isn't very clear.
What I am trying to do is get a google sheet to automatically calculate how many lengths of a material I will need to cover an area, hopefully to include a mix if needed. There are three different lengths of…
BlackShad
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- 5
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1 answer
SCIP constraint not satisfied
I am new to using SCIP, and I can't figure out why SCIP is not satisfying the constraints of my ILP. I have specified my ILP in the .lp format as described by IBM.
For example, consider the following constraints:
X0 - X1 - 5z_0_1_0 < 0
X1 - X0 -…
vimodev
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1 answer
Converting a simple conditional statement constraint into linear equation
I am using PuLP method to optimize a problem. I have a simple conditional statement as:
If A = 0, x = 0
Else if A>0, x = 1
How can I change it into mathematical equation (or a list of equations) if I want to use it as a constraint in…
aaloksk
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0
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1 answer
How to extract variables that equal a certain value in pyomo?
I am building a linear optimization model and trying to extract key information from my decision variable values. instance.x.display() displays the following sample
x : Size=121, Index=x_index
Key : Lower : Value : Upper : Fixed : Stale :…
Berbatov
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- 2
0
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1 answer
Python PulP linear optimisation for off-grid PV and battery system
I'm trying to use linear optimisation to minimise the size of solar PV and battery for an off-grid property. I have solar irradiance data and household energy consumption data - I have created a year's worth (8760 data points) of the data below.
I…
jmcq2
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- 3
0
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2 answers
model.update performance in the model
I have a question about performance of the model.update in the gurobipy library.
Let's say I have a list of objects which I want to add as a variable to the model, also I want to add a constraint to each of this object, to do that I have a for loop…
Ryszard Eggink
- 173
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Example for SimplexSolver in Apache Commons Maths 3.6.1
I am new to linear optimization and currently trying to use the SimplexSolver.class from org.apache.commons.math3.optim.linear.
So I looked up some examples on how to use it, to understand it and also to recall what the Simplex Algorithm exactly…
Mr. Moose
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0
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1 answer
Gurobi says the model is infeasible, yet I can come up with a solution by hand. Python implementation
Here is my model. Gurobi says its infeasible. My apologies if its hard to follow.
from gurobipy import Model, GRB
f = Model()
num_steps = 3
steps = [*range(num_steps)]
steps_for_C = [*range(num_steps + 1)]
A = f.addVar(0, float('inf'), name =…
midav
- 91
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