Questions tagged [extreme-rays]
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6
questions
6
votes
1answer
99 views
Extreme rays of a small polyhedral cone: How do I get them?
In a nutshell
I have a small 2-dimensional polyhedral cone.
$$C=\{(x_1,x_2): 2x_1-x_2 \leq 0, x_1+3x_2 \leq 0\}$$
I am looking for a simple, illustrative, procedure to get its extreme rays.
Any ...
5
votes
1answer
89 views
Find Extreme direction of equality constraints
I think this is a very basic question, but I failed to find an algorithm for this...
When I have a set of inequality constraints, $Ax \leq b$ as my feasible region, I can set $b = 0$ and find $n-1$ ...
6
votes
1answer
231 views
Extreme point and extreme ray of a network flow problem
"It is a well-known result in network flow theory that an extreme point and an extreme ray of the polyhedron defined by the convex hull of feasible region corresponds to a path and cycle (resp.) ...
3
votes
2answers
290 views
How to get an extreme ray of an LP from Gurobi
I am working on a problem of form
\begin{equation}
\begin{array}{l @{\quad} l}
\mathrm{max}_{x, u} & p^{\top} u
\\
\text{st.} & A u + a x \leq 0
\\
& x \in \{0, 1\...
9
votes
1answer
159 views
Extreme rays in polymake
I am trying to find extreme rays of a polyhedral cone using polymake. My understanding is that in a cone, every feasible solution is also a ray and an extreme ray is a ray that cannot be written as ...
12
votes
2answers
641 views
Generating all extreme rays
I am trying to understand a problem and would like to generate all extreme rays for a given set of linear constraints. With the Python interface of CPLEX, I was able to generate a single ray (not sure ...