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Linear Programming Simplex Method

Optimizes a linear objective by moving between vertices of a feasible region.

Quick Facts

Compact metadata for implementation and discovery.

Category
Optimization
Difficulty
Advanced
Family
Linear Programming
Tier
Core
Status
Verified
Review
Source Checked
Sources
1
Formulas
1
Relationships
7
Code example
Not ready
Visualization
Ready
Aliases
Simplex Method

Overview

The Simplex Method follows edges of a polytope from one feasible corner to another until no adjacent corner improves the objective.

Core Concepts

objective functionlinear constraintslinear programmingiterative improvementstopping rule

Quick facts

Complexity

Runtime and memory behavior at a glance.

Best

O(mn)

Average

O(poly practical)

Worst

O(2^n)

Space

O(mn)

When to Use

  • Use Linear Programming Simplex Method when you need to maintain a feasible basic solution.
  • Use it for resource allocation with inputs like linear objective.
  • Use it when you can define a score, objective, constraint, or feasibility test clearly.
  • Use it when the Linear Programming tradeoff is acceptable for the problem size.

When Not to Use

  • Avoid it when the objective is noisy or changing and the algorithm assumes stable feedback.
  • Avoid it when O(2^n) worst-case behavior is too costly for the expected input size.
  • Avoid it when the required output is not optimal solution.

What It Does

  • Maintains a feasible basic solution
  • Pivots to improving neighboring vertices

Use Cases

  • Resource allocation
  • Operations research
  • Linear constrained optimization

Inputs

  • Linear objective
  • Linear constraints

Outputs

  • Optimal solution
  • Unbounded or infeasible result

Key Formulas (1)

Linear objective

maximize cT x subject to A x ≤ b and x ≥ 0
maximize c^T x subject to A x <= b and x >= 0

States the kind of linear objective and constraints that Simplex moves through.

Pseudocode

  1. 1.Convert the problem to tableau form
  2. 2.Choose an entering variable
  3. 3.Choose a leaving variable by ratio test
  4. 4.Pivot the tableau
  5. 5.Repeat until no improving pivot remains

Canonical Example

Input
objective = minimize (x - 3)^2, start = x = 0
Output
x moves toward 3
Explanation
Linear Programming Simplex Method: The algorithm repeatedly improves a candidate solution according to the objective.

Implementation Notes

  • Keep the input contract explicit: Linear objective; Linear constraints.
  • Use this step as the implementation spine: Convert the problem to tableau form.
  • Then preserve the next state change: Choose an entering variable.
  • Log objective values across iterations so regressions and stalled progress are visible.

Common Pitfalls

  • Worst-case time is exponential, but Simplex is very effective on many practical problems.
  • Stopping after one good-looking result without checking convergence or constraints.
  • Returning optimal solution without handling empty, invalid, or boundary inputs.

Interactive Mechanism Walkthrough

Iterative Convergence & State Trajectory

Show an objective improving as it moves from corner to corner.

Linear Programming Simplex Method mechanism walkthrough step 1 of 5x₀x₁x₂x*
Step 1 of 5: Convert the problem to tableau form
polytope-vertices

Notes

Linear Programming Simplex Method operates in O(poly practical) time and O(mn) space within the Linear Programming family. Key governing relation: maximize c^T x subject to A x <= b and x >= 0. Often compared with Branch and Bound and Coordinate Descent.

Sources (1)

What each reference supports for this entry.

Linear Programming and Extensions

Book

Classic reference for the simplex method and linear programming foundations.

Explore Next

Good next jumps from the relationship graph, ranked for useful discovery.

Often paired withBranch and Bound

Simplex can solve relaxations used inside integer branch-and-bound.

Alternative toInterior Point Method

Simplex walks along polytope vertices, while interior-point methods move through the feasible interior.

Tags

OptimizationLinear ProgrammingClassic