4.7 Sensitivity analysis in Linear Programming
|
|
|
- Joan Grant
- 5 years ago
- Views:
Transcription
1 4.7 Sensitivity analysis in Linear Programming Evaluate the sensitivity of an optimal solution with respect to variations in the data (model parameters). Example: Production planning max n j n a j p j ij x x j j b i x j profit availability i-th resource i m j n E. Amaldi Foundations of Operations Research. Politecnico di Milano
2 4.7. Geometric interpretation Example: x max x + x ½ x + x x + x 4 x, x 4 optimal solution ½ x + x = 4/ x * = 4/ with z * = 8/ 4 x x + x = 4 E. Amaldi Foundations of Operations Research. Politecnico di Milano
3 Variation of the objective function coefficients x If c x + x = z with ½ c 4 optimal solution x * 4/ = with z 4/ * = 8/ x + x = ½ x + x = 4 x x + x = 4 max x + x ½ x + x x + x 4 x, x E. Amaldi Foundations of Operations Research. Politecnico di Milano
4 Variations of the right-hand-side terms 4 x x * / x * =, z * = / + 8/ = / 8/ optimal solution x * ½ x + x = + 4/ 4/ x * = with z * = 8/ 4 x x + x = 4 max x + x ½ x +x + x + x 4 x, x E. Amaldi Foundations of Operations Research. Politecnico di Milano 4
5 Definition: The shadow price of the i-th resourse = maximum price the company is willing to pay to buy an additional unit of i-th resource. Shadow price of the first resource = / 8/ = / = z * E. Amaldi Foundations of Operations Research. Politecnico di Milano
6 4.7. Sensitivity analysis: algebraic form Evaluate the sensitivity of an optimal solution when the model parameters (c j, a ij, b i ) vary. Given min c T x and optimal basic solution x * (P) Ax = b x x B* = B - b x N* = Within which limits the basis B remains optimal? Conditions: ) B - b feasibility ) c T N = c T N c T B B - N T optimality Topic of the 4th comupter laboratory session. E. Amaldi Foundations of Operations Research. Politecnico di Milano 6
7 Variation of right-hand-side terms b b+ δ k e k with e k = k k n The basis B with the basic solution remains optimal as long as x * = B- (b+ δ k e k ) c N do not vary B - (b+ δ k e k ) B - b -δ k B - e k m inequalities that define an interval of variation for δ k E. Amaldi Foundations of Operations Research. Politecnico di Milano 7
8 The basis B remains optimal, but the optimal basic feasible solution changes. The objective function values goes from c T B B - b to c T B B - (b+ δ k e k ) z * = c T B B - (δ k e k ) = δ k y * k y *T shadow price! z * b k optimal value of the dual variable E. Amaldi Foundations of Operations Research. Politecnico di Milano 8
9 Variation of the cost coefficients Given c c+ δ k e k abasisb remains optimal as long as c T N c T N c T B B - N In such a case, the optimal basic (feasible) solution does not change: x * B = B - b x * N = E. Amaldi Foundations of Operations Research. Politecnico di Milano 9
10 If x k is a nonbasic variable c T N = c T N c T B B - N T con c T B = c T B c T N = (c T N + δ k e T k) c T B B - N = (c T N c T B B - N ) + δ k e T k = c T N + δ k e T k T δ k -c k Reduced cost = max decrease of c k for which B remains optimal ( larger decrease c k < ) z * = since z * = c T B B - b= c T B x * B E. Amaldi Foundations of Operations Research. Politecnico di Milano
11 If x k is a basic variable c T N = c T N c T B B - N T with c T N = c T N c T N = c T N (c T B + δ k e T k) B - N = (c T N c T B B - N ) - δ k e T k B - N c T N δ k T k T c T N δ k T k where T k k-the row of B - N n-m inequalities that define a variation interval for δ k E. Amaldi Foundations of Operations Research. Politecnico di Milano
12 In such a case z * = δ k e T k B - b= δ k x * k x * B z * c k Similar analysis for the coefficients a ij E. Amaldi Foundations of Operations Research. Politecnico di Milano
13 Example: sensitivity analysis Initial tableau: initial basis min c T x Ax = b x x x x x 4 x x 6 -z x 4 x x 6 6 b I E. Amaldi Foundations of Operations Research. Politecnico di Milano
14 Optimal tableau: c T N c T N c T B B - N pivoting operations premultiply by B - x x x x 4 x x 6 -z 7/ 7/ 6/ / x / / / -/ x 8/ / -/ / x B - b B - N B - I = B - E. Amaldi Foundations of Operations Research. Politecnico di Milano 4
15 E. Amaldi Foundations of Operations Research. Politecnico di Milano Thus x B = 6 x x x B B B - b= 4 8 c B = x N = 4 x x x c N = y T = c T B B - = 6 Optimal dual solution:
16 E. Amaldi Foundations of Operations Research. Politecnico di Milano 6 Variations of b : b b+ δ k e k e k = k x * B = B- (b+ δ k e k ) remains optimal as long as B - (b+ δ k e k ) B - b - δ k B - e k k =,, k = : δ 4 8 -/ δ 4 k = : -4 δ k = : -4 δ
17 E. Amaldi Foundations of Operations Research. Politecnico di Milano 7 Variations of c : c c+ δ k c k For x k basic, B remains optimal if and only if c T N δ k e T k B - N c N = 6 7 B - N = reduced cost δ -7/ δ 4-6/ δ -/ For x k nonbasic, B remains otpimal if and only if δ k -c k
18 k = : δ k = : k = 6: δ / / δ 6 7/ E. Amaldi Foundations of Operations Research. Politecnico di Milano 8
4.6 Linear Programming duality
4.6 Linear Programming duality To any minimization (maximization) LP we can associate a closely related maximization (minimization) LP Different spaces and objective functions but in general same optimal
SAMPLE QUESTIONS. b = (30, 20, 40, 10, 50) T, c = (650, 1000, 1350, 1600, 1900) T.
SAMPLE QUESTIONS. (a) We first set up some constant vectors for our constraints. Let b = (30, 0, 40, 0, 0) T, c = (60, 000, 30, 600, 900) T. Then we set up variables x ij, where i, j and i + j 6. By using
The use of shadow price is an example of sensitivity analysis. Duality theory can be applied to do other kind of sensitivity analysis:
Sensitivity analysis The use of shadow price is an example of sensitivity analysis. Duality theory can be applied to do other kind of sensitivity analysis: Changing the coefficient of a nonbasic variable
Part 1. The Review of Linear Programming
In the name of God Part 1. The Review of Linear Programming 1.5. Spring 2010 Instructor: Dr. Masoud Yaghini Outline Introduction Formulation of the Dual Problem Primal-Dual Relationship Economic Interpretation
OPERATIONS RESEARCH. Michał Kulej. Business Information Systems
OPERATIONS RESEARCH Michał Kulej Business Information Systems The development of the potential and academic programmes of Wrocław University of Technology Project co-financed by European Union within European
4.5 Simplex method. min z = c T x s.v. Ax = b. LP in standard form
4.5 Simplex method min z = c T x s.v. Ax = b x 0 LP in standard form Examine a sequence of basic feasible solutions with non increasing objective function value until an optimal solution is reached or
Math Models of OR: Some Definitions
Math Models of OR: Some Definitions John E. Mitchell Department of Mathematical Sciences RPI, Troy, NY 12180 USA September 2018 Mitchell Some Definitions 1 / 20 Active constraints Outline 1 Active constraints
Introduction to linear programming using LEGO.
Introduction to linear programming using LEGO. 1 The manufacturing problem. A manufacturer produces two pieces of furniture, tables and chairs. The production of the furniture requires the use of two different
Special cases of linear programming
Special cases of linear programming Infeasible solution Multiple solution (infinitely many solution) Unbounded solution Degenerated solution Notes on the Simplex tableau 1. The intersection of any basic
Worked Examples for Chapter 5
Worked Examples for Chapter 5 Example for Section 5.2 Construct the primal-dual table and the dual problem for the following linear programming model fitting our standard form. Maximize Z = 5 x 1 + 4 x
Dual Basic Solutions. Observation 5.7. Consider LP in standard form with A 2 R m n,rank(a) =m, and dual LP:
Dual Basic Solutions Consider LP in standard form with A 2 R m n,rank(a) =m, and dual LP: Observation 5.7. AbasisB yields min c T x max p T b s.t. A x = b s.t. p T A apple c T x 0 aprimalbasicsolutiongivenbyx
Math Models of OR: Sensitivity Analysis
Math Models of OR: Sensitivity Analysis John E. Mitchell Department of Mathematical Sciences RPI, Troy, NY 8 USA October 8 Mitchell Sensitivity Analysis / 9 Optimal tableau and pivot matrix Outline Optimal
Slack Variable. Max Z= 3x 1 + 4x 2 + 5X 3. Subject to: X 1 + X 2 + X x 1 + 4x 2 + X X 1 + X 2 + 4X 3 10 X 1 0, X 2 0, X 3 0
Simplex Method Slack Variable Max Z= 3x 1 + 4x 2 + 5X 3 Subject to: X 1 + X 2 + X 3 20 3x 1 + 4x 2 + X 3 15 2X 1 + X 2 + 4X 3 10 X 1 0, X 2 0, X 3 0 Standard Form Max Z= 3x 1 +4x 2 +5X 3 + 0S 1 + 0S 2
Yinyu Ye, MS&E, Stanford MS&E310 Lecture Note #06. The Simplex Method
The Simplex Method Yinyu Ye Department of Management Science and Engineering Stanford University Stanford, CA 94305, U.S.A. http://www.stanford.edu/ yyye (LY, Chapters 2.3-2.5, 3.1-3.4) 1 Geometry of Linear
CO350 Linear Programming Chapter 6: The Simplex Method
CO50 Linear Programming Chapter 6: The Simplex Method rd June 2005 Chapter 6: The Simplex Method 1 Recap Suppose A is an m-by-n matrix with rank m. max. c T x (P ) s.t. Ax = b x 0 On Wednesday, we learned
Chap6 Duality Theory and Sensitivity Analysis
Chap6 Duality Theory and Sensitivity Analysis The rationale of duality theory Max 4x 1 + x 2 + 5x 3 + 3x 4 S.T. x 1 x 2 x 3 + 3x 4 1 5x 1 + x 2 + 3x 3 + 8x 4 55 x 1 + 2x 2 + 3x 3 5x 4 3 x 1 ~x 4 0 If we
March 13, Duality 3
15.53 March 13, 27 Duality 3 There are concepts much more difficult to grasp than duality in linear programming. -- Jim Orlin The concept [of nonduality], often described in English as "nondualism," is
1 Review Session. 1.1 Lecture 2
1 Review Session Note: The following lists give an overview of the material that was covered in the lectures and sections. Your TF will go through these lists. If anything is unclear or you have questions
Introduction to Mathematical Programming IE406. Lecture 13. Dr. Ted Ralphs
Introduction to Mathematical Programming IE406 Lecture 13 Dr. Ted Ralphs IE406 Lecture 13 1 Reading for This Lecture Bertsimas Chapter 5 IE406 Lecture 13 2 Sensitivity Analysis In many real-world problems,
Review Solutions, Exam 2, Operations Research
Review Solutions, Exam 2, Operations Research 1. Prove the weak duality theorem: For any x feasible for the primal and y feasible for the dual, then... HINT: Consider the quantity y T Ax. SOLUTION: To
Note 3: LP Duality. If the primal problem (P) in the canonical form is min Z = n (1) then the dual problem (D) in the canonical form is max W = m (2)
Note 3: LP Duality If the primal problem (P) in the canonical form is min Z = n j=1 c j x j s.t. nj=1 a ij x j b i i = 1, 2,..., m (1) x j 0 j = 1, 2,..., n, then the dual problem (D) in the canonical
Brief summary of linear programming and duality: Consider the linear program in standard form. (P ) min z = cx. x 0. (D) max yb. z = c B x B + c N x N
Brief summary of linear programming and duality: Consider the linear program in standard form (P ) min z = cx s.t. Ax = b x 0 where A R m n, c R 1 n, x R n 1, b R m 1,and its dual (D) max yb s.t. ya c.
IEOR 4404 Homework #4 Intro OR: Deterministic Models February 28, 2011 Prof. Jay Sethuraman Page 1 of 5. Homework #4
IEOR 444 Homework #4 Intro OR: Deterministic Models February 28, 211 Prof. Jay Sethuraman Page 1 of 5 Homework #4 1. a. What is the optimal production mix? What contribution can the firm anticipate by
maxz = 3x 1 +4x 2 2x 1 +x 2 6 2x 1 +3x 2 9 x 1,x 2
ex-5.-5. Foundations of Operations Research Prof. E. Amaldi 5. Branch-and-Bound Given the integer linear program maxz = x +x x +x 6 x +x 9 x,x integer solve it via the Branch-and-Bound method (solving
Sensitivity Analysis and Duality
Sensitivity Analysis and Duality Part II Duality Based on Chapter 6 Introduction to Mathematical Programming: Operations Research, Volume 1 4th edition, by Wayne L. Winston and Munirpallam Venkataramanan
MATH2070 Optimisation
MATH2070 Optimisation Linear Programming Semester 2, 2012 Lecturer: I.W. Guo Lecture slides courtesy of J.R. Wishart Review The standard Linear Programming (LP) Problem Graphical method of solving LP problem
MAT016: Optimization
MAT016: Optimization M.El Ghami e-mail: melghami@ii.uib.no URL: http://www.ii.uib.no/ melghami/ March 29, 2011 Outline for today The Simplex method in matrix notation Managing a production facility The
1 Simplex and Matrices
1 Simplex and Matrices We will begin with a review of matrix multiplication. A matrix is simply an array of numbers. If a given array has m rows and n columns, then it is called an m n (or m-by-n) matrix.
4.5 Simplex method. LP in standard form: min z = c T x s.t. Ax = b
4.5 Simplex method LP in standard form: min z = c T x s.t. Ax = b x 0 George Dantzig (1914-2005) Examine a sequence of basic feasible solutions with non increasing objective function values until an optimal
3. Vector spaces 3.1 Linear dependence and independence 3.2 Basis and dimension. 5. Extreme points and basic feasible solutions
A. LINEAR ALGEBRA. CONVEX SETS 1. Matrices and vectors 1.1 Matrix operations 1.2 The rank of a matrix 2. Systems of linear equations 2.1 Basic solutions 3. Vector spaces 3.1 Linear dependence and independence
6.2: The Simplex Method: Maximization (with problem constraints of the form )
6.2: The Simplex Method: Maximization (with problem constraints of the form ) 6.2.1 The graphical method works well for solving optimization problems with only two decision variables and relatively few
Linear Programming Duality
Summer 2011 Optimization I Lecture 8 1 Duality recap Linear Programming Duality We motivated the dual of a linear program by thinking about the best possible lower bound on the optimal value we can achieve
Introduce the idea of a nondegenerate tableau and its analogy with nondenegerate vertices.
2 JORDAN EXCHANGE REVIEW 1 Lecture Outline The following lecture covers Section 3.5 of the textbook [?] Review a labeled Jordan exchange with pivoting. Introduce the idea of a nondegenerate tableau and
Understanding the Simplex algorithm. Standard Optimization Problems.
Understanding the Simplex algorithm. Ma 162 Spring 2011 Ma 162 Spring 2011 February 28, 2011 Standard Optimization Problems. A standard maximization problem can be conveniently described in matrix form
3. Duality: What is duality? Why does it matter? Sensitivity through duality.
1 Overview of lecture (10/5/10) 1. Review Simplex Method 2. Sensitivity Analysis: How does solution change as parameters change? How much is the optimal solution effected by changing A, b, or c? How much
MATH 445/545 Test 1 Spring 2016
MATH 445/545 Test Spring 06 Note the problems are separated into two sections a set for all students and an additional set for those taking the course at the 545 level. Please read and follow all of these
Math Models of OR: Handling Upper Bounds in Simplex
Math Models of OR: Handling Upper Bounds in Simplex John E. Mitchell Department of Mathematical Sciences RPI, Troy, NY 280 USA September 208 Mitchell Handling Upper Bounds in Simplex / 8 Introduction Outline
Foundations of Operations Research
Solved exercises for the course of Foundations of Operations Research Roberto Cordone Gomory cuts Given the ILP problem maxf = 4x 1 +3x 2 2x 1 +x 2 11 x 1 +2x 2 6 x 1,x 2 N solve it with the Gomory cutting
END3033 Operations Research I Sensitivity Analysis & Duality. to accompany Operations Research: Applications and Algorithms Fatih Cavdur
END3033 Operations Research I Sensitivity Analysis & Duality to accompany Operations Research: Applications and Algorithms Fatih Cavdur Introduction Consider the following problem where x 1 and x 2 corresponds
Math Models of OR: The Revised Simplex Method
Math Models of OR: The Revised Simplex Method John E. Mitchell Department of Mathematical Sciences RPI, Troy, NY 12180 USA September 2018 Mitchell The Revised Simplex Method 1 / 25 Motivation Outline 1
Farkas Lemma, Dual Simplex and Sensitivity Analysis
Summer 2011 Optimization I Lecture 10 Farkas Lemma, Dual Simplex and Sensitivity Analysis 1 Farkas Lemma Theorem 1. Let A R m n, b R m. Then exactly one of the following two alternatives is true: (i) x
Sensitivity Analysis and Duality in LP
Sensitivity Analysis and Duality in LP Xiaoxi Li EMS & IAS, Wuhan University Oct. 13th, 2016 (week vi) Operations Research (Li, X.) Sensitivity Analysis and Duality in LP Oct. 13th, 2016 (week vi) 1 /
A Review of Linear Programming
A Review of Linear Programming Instructor: Farid Alizadeh IEOR 4600y Spring 2001 February 14, 2001 1 Overview In this note we review the basic properties of linear programming including the primal simplex
CO350 Linear Programming Chapter 6: The Simplex Method
CO350 Linear Programming Chapter 6: The Simplex Method 8th June 2005 Chapter 6: The Simplex Method 1 Minimization Problem ( 6.5) We can solve minimization problems by transforming it into a maximization
5 Integer Linear Programming (ILP) E. Amaldi Foundations of Operations Research Politecnico di Milano 1
5 Integer Linear Programming (ILP) E. Amaldi Foundations of Operations Research Politecnico di Milano 1 Definition: An Integer Linear Programming problem is an optimization problem of the form (ILP) min
min3x 1 + 4x 2 + 5x 3 2x 1 + 2x 2 + x 3 6 x 1 + 2x 2 + 3x 3 5 x 1, x 2, x 3 0.
ex-.-. Foundations of Operations Research Prof. E. Amaldi. Dual simplex algorithm Given the linear program minx + x + x x + x + x 6 x + x + x x, x, x. solve it via the dual simplex algorithm. Describe
Chapter 1 Linear Programming. Paragraph 5 Duality
Chapter 1 Linear Programming Paragraph 5 Duality What we did so far We developed the 2-Phase Simplex Algorithm: Hop (reasonably) from basic solution (bs) to bs until you find a basic feasible solution
Section 4.1 Solving Systems of Linear Inequalities
Section 4.1 Solving Systems of Linear Inequalities Question 1 How do you graph a linear inequality? Question 2 How do you graph a system of linear inequalities? Question 1 How do you graph a linear inequality?
Part 1. The Review of Linear Programming
In the name of God Part 1. The Review of Linear Programming 1.2. Spring 2010 Instructor: Dr. Masoud Yaghini Outline Introduction Basic Feasible Solutions Key to the Algebra of the The Simplex Algorithm
F 1 F 2 Daily Requirement Cost N N N
Chapter 5 DUALITY 5. The Dual Problems Every linear programming problem has associated with it another linear programming problem and that the two problems have such a close relationship that whenever
Math Models of OR: Extreme Points and Basic Feasible Solutions
Math Models of OR: Extreme Points and Basic Feasible Solutions John E. Mitchell Department of Mathematical Sciences RPI, Troy, NY 1180 USA September 018 Mitchell Extreme Points and Basic Feasible Solutions
Optimum Solution of Linear Programming Problem by Simplex Method
Optimum Solution of Linear Programming Problem by Simplex Method U S Hegde 1, S Uma 2, Aravind P N 3 1 Associate Professor & HOD, Department of Mathematics, Sir M V I T, Bangalore, India 2 Associate Professor,
Linear programming: algebra
: algebra CE 377K March 26, 2015 ANNOUNCEMENTS Groups and project topics due soon Announcements Groups and project topics due soon Did everyone get my test email? Announcements REVIEW geometry Review geometry
Chapter 2: Preliminaries and elements of convex analysis
Chapter 2: Preliminaries and elements of convex analysis Edoardo Amaldi DEIB Politecnico di Milano edoardo.amaldi@polimi.it Website: http://home.deib.polimi.it/amaldi/opt-14-15.shtml Academic year 2014-15
Duality Theory, Optimality Conditions
5.1 Duality Theory, Optimality Conditions Katta G. Murty, IOE 510, LP, U. Of Michigan, Ann Arbor We only consider single objective LPs here. Concept of duality not defined for multiobjective LPs. Every
Midterm Review. Yinyu Ye Department of Management Science and Engineering Stanford University Stanford, CA 94305, U.S.A.
Midterm Review Yinyu Ye Department of Management Science and Engineering Stanford University Stanford, CA 94305, U.S.A. http://www.stanford.edu/ yyye (LY, Chapter 1-4, Appendices) 1 Separating hyperplane
II. Analysis of Linear Programming Solutions
Optimization Methods Draft of August 26, 2005 II. Analysis of Linear Programming Solutions Robert Fourer Department of Industrial Engineering and Management Sciences Northwestern University Evanston, Illinois
Lesson 27 Linear Programming; The Simplex Method
Lesson Linear Programming; The Simplex Method Math 0 April 9, 006 Setup A standard linear programming problem is to maximize the quantity c x + c x +... c n x n = c T x subject to constraints a x + a x
OPTIMIZATION. joint course with. Ottimizzazione Discreta and Complementi di R.O. Edoardo Amaldi. DEIB Politecnico di Milano
OPTIMIZATION joint course with Ottimizzazione Discreta and Complementi di R.O. Edoardo Amaldi DEIB Politecnico di Milano edoardo.amaldi@polimi.it Website: http://home.deib.polimi.it/amaldi/opt-15-16.shtml
21. Solve the LP given in Exercise 19 using the big-m method discussed in Exercise 20.
Extra Problems for Chapter 3. Linear Programming Methods 20. (Big-M Method) An alternative to the two-phase method of finding an initial basic feasible solution by minimizing the sum of the artificial
56:171 Operations Research Midterm Exam - October 26, 1989 Instructor: D.L. Bricker
56:171 Operations Research Midterm Exam - October 26, 1989 Instructor: D.L. Bricker Answer all of Part One and two (of the four) problems of Part Two Problem: 1 2 3 4 5 6 7 8 TOTAL Possible: 16 12 20 10
+ 5x 2. = x x. + x 2. Transform the original system into a system x 2 = x x 1. = x 1
University of California, Davis Department of Agricultural and Resource Economics ARE 5 Optimization with Economic Applications Lecture Notes Quirino Paris The Pivot Method for Solving Systems of Equations...................................
Chapter 4 The Simplex Algorithm Part I
Chapter 4 The Simplex Algorithm Part I Based on Introduction to Mathematical Programming: Operations Research, Volume 1 4th edition, by Wayne L. Winston and Munirpallam Venkataramanan Lewis Ntaimo 1 Modeling
Foundations of Operations Research
Solved exercises for the course of Foundations of Operations Research Roberto Cordone The dual simplex method Given the following LP problem: maxz = 5x 1 +8x 2 x 1 +x 2 6 5x 1 +9x 2 45 x 1,x 2 0 1. solve
Simplex tableau CE 377K. April 2, 2015
CE 377K April 2, 2015 Review Reduced costs Basic and nonbasic variables OUTLINE Review by example: simplex method demonstration Outline Example You own a small firm producing construction materials for
1 Answer Key for exam2162sp07 vl
Ma 162 College Algebra Second Exam vl 9 1 Answer Key for exam2162sp07 vl 1. [ x =, 2, y =, 3, z =, 1, w =, 3, Mary, [63.5, 2, 1]] 2. ABC: 1 L1 L2 1CDE:L1 11 L2 3. P =1.8 x +1.8 y +1.5 z 0 x,0 y 9 x +10y
UNIVERSITY OF KWA-ZULU NATAL
UNIVERSITY OF KWA-ZULU NATAL EXAMINATIONS: June 006 Solutions Subject, course and code: Mathematics 34 MATH34P Multiple Choice Answers. B. B 3. E 4. E 5. C 6. A 7. A 8. C 9. A 0. D. C. A 3. D 4. E 5. B
CO350 Linear Programming Chapter 8: Degeneracy and Finite Termination
CO350 Linear Programming Chapter 8: Degeneracy and Finite Termination 27th June 2005 Chapter 8: Finite Termination 1 The perturbation method Recap max c T x (P ) s.t. Ax = b x 0 Assumption: B is a feasible
x 4 = 40 +2x 5 +6x x 6 x 1 = 10 2x x 6 x 3 = 20 +x 5 x x 6 z = 540 3x 5 x 2 3x 6 x 4 x 5 x 6 x x
MATH 4 A Sensitivity Analysis Example from lectures The following examples have been sometimes given in lectures and so the fractions are rather unpleasant for testing purposes. Note that each question
Ω R n is called the constraint set or feasible set. x 1
1 Chapter 5 Linear Programming (LP) General constrained optimization problem: minimize subject to f(x) x Ω Ω R n is called the constraint set or feasible set. any point x Ω is called a feasible point We
LINEAR PROGRAMMING 2. In many business and policy making situations the following type of problem is encountered:
LINEAR PROGRAMMING 2 In many business and policy making situations the following type of problem is encountered: Maximise an objective subject to (in)equality constraints. Mathematical programming provides
4. Duality and Sensitivity
4. Duality and Sensitivity For every instance of an LP, there is an associated LP known as the dual problem. The original problem is known as the primal problem. There are two de nitions of the dual pair
Thursday, May 24, Linear Programming
Linear Programming Linear optimization problems max f(x) g i (x) b i x j R i =1,...,m j =1,...,n Optimization problem g i (x) f(x) When and are linear functions Linear Programming Problem 1 n max c x n
Sensitivity Analysis
Dr. Maddah ENMG 500 /9/07 Sensitivity Analysis Changes in the RHS (b) Consider an optimal LP solution. Suppose that the original RHS (b) is changed from b 0 to b new. In the following, we study the affect
CO 602/CM 740: Fundamentals of Optimization Problem Set 4
CO 602/CM 740: Fundamentals of Optimization Problem Set 4 H. Wolkowicz Fall 2014. Handed out: Wednesday 2014-Oct-15. Due: Wednesday 2014-Oct-22 in class before lecture starts. Contents 1 Unique Optimum
CSC Design and Analysis of Algorithms. LP Shader Electronics Example
CSC 80- Design and Analysis of Algorithms Lecture (LP) LP Shader Electronics Example The Shader Electronics Company produces two products:.eclipse, a portable touchscreen digital player; it takes hours
1. Introduce slack variables for each inequaility to make them equations and rewrite the objective function in the form ax by cz... + P = 0.
3.4 Simplex Method If a linear programming problem has more than 2 variables, solving graphically is not the way to go. Instead, we ll use a more methodical, numeric process called the Simplex Method.
Math Homework 3: solutions. 1. Consider the region defined by the following constraints: x 1 + x 2 2 x 1 + 2x 2 6
Math 7502 Homework 3: solutions 1. Consider the region defined by the following constraints: x 1 + x 2 2 x 1 + 2x 2 6 x 1, x 2 0. (i) Maximize 4x 1 + x 2 subject to the constraints above. (ii) Minimize
IP Cut Homework from J and B Chapter 9: 14, 15, 16, 23, 24, You wish to solve the IP below with a cutting plane technique.
IP Cut Homework from J and B Chapter 9: 14, 15, 16, 23, 24, 31 14. You wish to solve the IP below with a cutting plane technique. Maximize 4x 1 + 2x 2 + x 3 subject to 14x 1 + 10x 2 + 11x 3 32 10x 1 +
min 4x 1 5x 2 + 3x 3 s.t. x 1 + 2x 2 + x 3 = 10 x 1 x 2 6 x 1 + 3x 2 + x 3 14
The exam is three hours long and consists of 4 exercises. The exam is graded on a scale 0-25 points, and the points assigned to each question are indicated in parenthesis within the text. If necessary,
MVE165/MMG631 Linear and integer optimization with applications Lecture 5 Linear programming duality and sensitivity analysis
MVE165/MMG631 Linear and integer optimization with applications Lecture 5 Linear programming duality and sensitivity analysis Ann-Brith Strömberg 2017 03 29 Lecture 4 Linear and integer optimization with
56:171 Operations Research Midterm Exam--15 October 2002
Name 56:171 Operations Research Midterm Exam--15 October 2002 Possible Score 1. True/False 25 _ 2. LP sensitivity analysis 25 _ 3. Transportation problem 15 _ 4. LP tableaux 15 _ Total 80 _ Part I: True(+)
1. Algebraic and geometric treatments Consider an LP problem in the standard form. x 0. Solutions to the system of linear equations
The Simplex Method Most textbooks in mathematical optimization, especially linear programming, deal with the simplex method. In this note we study the simplex method. It requires basically elementary linear
Lecture 4: Algebra, Geometry, and Complexity of the Simplex Method. Reading: Sections 2.6.4, 3.5,
Lecture 4: Algebra, Geometry, and Complexity of the Simplex Method Reading: Sections 2.6.4, 3.5, 10.2 10.5 1 Summary of the Phase I/Phase II Simplex Method We write a typical simplex tableau as z x 1 x
Motivating examples Introduction to algorithms Simplex algorithm. On a particular example General algorithm. Duality An application to game theory
Instructor: Shengyu Zhang 1 LP Motivating examples Introduction to algorithms Simplex algorithm On a particular example General algorithm Duality An application to game theory 2 Example 1: profit maximization
UNIVERSITY of LIMERICK
UNIVERSITY of LIMERICK OLLSCOIL LUIMNIGH Department of Mathematics & Statistics Faculty of Science and Engineering END OF SEMESTER ASSESSMENT PAPER MODULE CODE: MS4303 SEMESTER: Spring 2018 MODULE TITLE:
Chapter 5 Linear Programming (LP)
Chapter 5 Linear Programming (LP) General constrained optimization problem: minimize f(x) subject to x R n is called the constraint set or feasible set. any point x is called a feasible point We consider
COT 6936: Topics in Algorithms! Giri Narasimhan. ECS 254A / EC 2443; Phone: x3748
COT 6936: Topics in Algorithms! Giri Narasimhan ECS 254A / EC 2443; Phone: x3748 giri@cs.fiu.edu https://moodle.cis.fiu.edu/v2.1/course/view.php?id=612 Gaussian Elimination! Solving a system of simultaneous
Simplex Algorithm Using Canonical Tableaus
41 Simplex Algorithm Using Canonical Tableaus Consider LP in standard form: Min z = cx + α subject to Ax = b where A m n has rank m and α is a constant In tableau form we record it as below Original Tableau
Linear Programming: Simplex Method CHAPTER The Simplex Tableau; Pivoting
CHAPTER 5 Linear Programming: 5.1. The Simplex Tableau; Pivoting Simplex Method In this section we will learn how to prepare a linear programming problem in order to solve it by pivoting using a matrix
Dr. S. Bourazza Math-473 Jazan University Department of Mathematics
Dr. Said Bourazza Department of Mathematics Jazan University 1 P a g e Contents: Chapter 0: Modelization 3 Chapter1: Graphical Methods 7 Chapter2: Simplex method 13 Chapter3: Duality 36 Chapter4: Transportation
AM 121 Introduction to Optimization: Models and Methods Example Questions for Midterm 1
AM 121 Introduction to Optimization: Models and Methods Example Questions for Midterm 1 Prof. Yiling Chen Fall 2018 Here are some practice questions to help to prepare for the midterm. The midterm will
Operations Research Lecture 6: Integer Programming
Operations Research Lecture 6: Integer Programming Notes taken by Kaiquan Xu@Business School, Nanjing University May 12th 2016 1 Integer programming (IP) formulations The integer programming (IP) is the
M340(921) Solutions Problem Set 6 (c) 2013, Philip D Loewen. g = 35y y y 3.
M340(92) Solutions Problem Set 6 (c) 203, Philip D Loewen. (a) If each pig is fed y kilograms of corn, y 2 kilos of tankage, and y 3 kilos of alfalfa, the cost per pig is g = 35y + 30y 2 + 25y 3. The nutritional
Introduction. Very efficient solution procedure: simplex method.
LINEAR PROGRAMMING Introduction Development of linear programming was among the most important scientific advances of mid 20th cent. Most common type of applications: allocate limited resources to competing
The Simplex Algorithm
8.433 Combinatorial Optimization The Simplex Algorithm October 6, 8 Lecturer: Santosh Vempala We proved the following: Lemma (Farkas). Let A R m n, b R m. Exactly one of the following conditions is true:.
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Math324 - Test Review 2 - Fall 206 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Determine the vertex of the parabola. ) f(x) = x 2-0x + 33 ) (0,
9.1 Linear Programs in canonical form
9.1 Linear Programs in canonical form LP in standard form: max (LP) s.t. where b i R, i = 1,..., m z = j c jx j j a ijx j b i i = 1,..., m x j 0 j = 1,..., n But the Simplex method works only on systems
TIM 206 Lecture 3: The Simplex Method
TIM 206 Lecture 3: The Simplex Method Kevin Ross. Scribe: Shane Brennan (2006) September 29, 2011 1 Basic Feasible Solutions Have equation Ax = b contain more columns (variables) than rows (constraints),
0.1 O. R. Katta G. Murty, IOE 510 Lecture slides Introductory Lecture. is any organization, large or small.
0.1 O. R. Katta G. Murty, IOE 510 Lecture slides Introductory Lecture Operations Research is the branch of science dealing with techniques for optimizing the performance of systems. System is any organization,