Solving Linear Programming Problems by Reducing to the Form with an Obvious Answer

The article considers a method for solving a linear programming problem (LPP), which requires finding the minimum or maximum of a linear functional on a set of non-negative solutions of a system of linear algebraic equations with the same unknowns. The method is obtained by improving the classical s...

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Main Author: Gleb D. Stepanov
Format: Article
Language:English
Published: Yaroslavl State University 2021-12-01
Series:Моделирование и анализ информационных систем
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Online Access:https://www.mais-journal.ru/jour/article/view/1569
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author Gleb D. Stepanov
author_facet Gleb D. Stepanov
author_sort Gleb D. Stepanov
collection DOAJ
description The article considers a method for solving a linear programming problem (LPP), which requires finding the minimum or maximum of a linear functional on a set of non-negative solutions of a system of linear algebraic equations with the same unknowns. The method is obtained by improving the classical simplex method, which when involving geometric considerations, in fact, generalizes the Gauss complete exclusion method for solving systems of equations. The proposed method, as well as the method of complete exceptions, proceeds from purely algebraic considerations. It consists of converting the entire LPP, including the objective function, into an equivalent problem with an obvious answer. For the convenience of converting the target functional, the equations are written as linear functionals on the left side and zeros on the right one. From the coefficients of the mentioned functionals, a matrix is formed, which is called the LPP matrix. The zero row of the matrix is the coefficients of the target functional, $a_{00}$ is its free member. The algorithms are described and justified in terms of the transformation of this matrix. In calculations the matrix is a calculation table. The method under consideration by analogy with the simplex method consists of three stages. At the first stage the LPP matrix is reduced to a special 1-canonical form. With such matrices one of the basic solutions of the system is obvious, and the target functional on it is $ a_{00}$, which is very convenient. At the second stage the resulting matrix is transformed into a similar matrix with non-positive elements of the zero column (except $a_{00}$), which entails the non-negativity of the basic solution. At the third stage the matrix is transformed into a matrix that provides non-negativity and optimality of the basic solution. For the second stage the analog of which in the simplex method uses an artificial basis and is the most time-consuming, two variants without artificial variables are given. When describing the first of them, along the way, a very easy-to-understand and remember analogue of the famous Farkas lemma is obtained. The other option is quite simple to use, but its full justification is difficult and will be separately published.
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spelling doaj-art-33d25d0670ea4e72a599fcaced14dd5a2025-08-20T03:22:03ZengYaroslavl State UniversityМоделирование и анализ информационных систем1818-10152313-54172021-12-0128443445110.18255/1818-1015-2021-4-434-4511200Solving Linear Programming Problems by Reducing to the Form with an Obvious AnswerGleb D. Stepanov0Voronezh State Pedagogical UniversityThe article considers a method for solving a linear programming problem (LPP), which requires finding the minimum or maximum of a linear functional on a set of non-negative solutions of a system of linear algebraic equations with the same unknowns. The method is obtained by improving the classical simplex method, which when involving geometric considerations, in fact, generalizes the Gauss complete exclusion method for solving systems of equations. The proposed method, as well as the method of complete exceptions, proceeds from purely algebraic considerations. It consists of converting the entire LPP, including the objective function, into an equivalent problem with an obvious answer. For the convenience of converting the target functional, the equations are written as linear functionals on the left side and zeros on the right one. From the coefficients of the mentioned functionals, a matrix is formed, which is called the LPP matrix. The zero row of the matrix is the coefficients of the target functional, $a_{00}$ is its free member. The algorithms are described and justified in terms of the transformation of this matrix. In calculations the matrix is a calculation table. The method under consideration by analogy with the simplex method consists of three stages. At the first stage the LPP matrix is reduced to a special 1-canonical form. With such matrices one of the basic solutions of the system is obvious, and the target functional on it is $ a_{00}$, which is very convenient. At the second stage the resulting matrix is transformed into a similar matrix with non-positive elements of the zero column (except $a_{00}$), which entails the non-negativity of the basic solution. At the third stage the matrix is transformed into a matrix that provides non-negativity and optimality of the basic solution. For the second stage the analog of which in the simplex method uses an artificial basis and is the most time-consuming, two variants without artificial variables are given. When describing the first of them, along the way, a very easy-to-understand and remember analogue of the famous Farkas lemma is obtained. The other option is quite simple to use, but its full justification is difficult and will be separately published.https://www.mais-journal.ru/jour/article/view/1569linear programminggauss methodsimplex methodlpp matrixresolving elementchoice rulefarkas lemmasystems of linear equationsnon-negative solution
spellingShingle Gleb D. Stepanov
Solving Linear Programming Problems by Reducing to the Form with an Obvious Answer
Моделирование и анализ информационных систем
linear programming
gauss method
simplex method
lpp matrix
resolving element
choice rule
farkas lemma
systems of linear equations
non-negative solution
title Solving Linear Programming Problems by Reducing to the Form with an Obvious Answer
title_full Solving Linear Programming Problems by Reducing to the Form with an Obvious Answer
title_fullStr Solving Linear Programming Problems by Reducing to the Form with an Obvious Answer
title_full_unstemmed Solving Linear Programming Problems by Reducing to the Form with an Obvious Answer
title_short Solving Linear Programming Problems by Reducing to the Form with an Obvious Answer
title_sort solving linear programming problems by reducing to the form with an obvious answer
topic linear programming
gauss method
simplex method
lpp matrix
resolving element
choice rule
farkas lemma
systems of linear equations
non-negative solution
url https://www.mais-journal.ru/jour/article/view/1569
work_keys_str_mv AT glebdstepanov solvinglinearprogrammingproblemsbyreducingtotheformwithanobviousanswer