Finding Vertices of Polyhedron with Simplex Method

  • Context: MHB 
  • Thread starter Thread starter evinda
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around finding the vertices of a polyhedron defined by a set of linear equations and constraints using the simplex method. Participants explore the implications of these equations, the setup of the simplex tableau, and the conditions for linear independence among the columns of the associated matrix.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant proposes a transformation of variables to ensure positivity for the simplex method, leading to a new set of equations.
  • Another participant questions the omission of constraints on the transformed variables, prompting a revision of the equations.
  • There is a discussion about the correct structure of the matrix representing the system, with participants debating the placement of columns and the total number of variables.
  • Participants explore the concept of linear independence and suggest methods to check it, including creating matrices and reducing them to column echelon form.
  • One participant expresses uncertainty about the independence of specific columns and the implications for the number of combinations to check.
  • There is a back-and-forth regarding the correct number of columns and variables, with some participants suggesting corrections to earlier claims.
  • Another participant attempts to clarify the process of checking for linear independence through matrix operations, but acknowledges a mistake in their earlier representation.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the correctness of the initial solutions or the structure of the matrix. There are multiple competing views regarding the setup of the simplex tableau and the implications of linear independence.

Contextual Notes

There are unresolved issues regarding the constraints on the transformed variables and the correct formulation of the matrix. The discussion also reflects varying interpretations of the linear independence of the columns and the implications for the simplex method.

  • #31
I like Serena said:
Normally a polyhedron consists of a number of vertices connected by edges, such that faces (polygons) are formed.
A polyhedron usually has a certain volume.
If there are 2 faces or less, it won't contain a volume, and is considered degenerate.
In this case we don't even have a face - only a single line segment. (Nerd)

So in this case we can say that if the line segment is one of the edges of a polyhedron , then its endpoints are vertices of the polyhedron. Right? (Thinking)
 
Physics news on Phys.org
  • #32
evinda said:
So in this case we can say that if the line segment is one of the edges of a polyhedron , then its endpoints are vertices of the polyhedron. Right? (Thinking)

Exactly. (Nod)
 
  • #33
I like Serena said:
Exactly. (Nod)

Nice... Thank you! (Smile)
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 21 ·
Replies
21
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 6 ·
Replies
6
Views
1K
  • · Replies 25 ·
Replies
25
Views
4K
Replies
1
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
3
Views
2K