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Interactive Editing of Linear and Mixed Integer Programming Models

IP.com Disclosure Number: IPCOM000036522D
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Ciriani, TA: AUTHOR [+4]

Abstract

The Model Manager is a matrix editor which allows an interactive editing of Linear Programming (LP) and Mixed Integer Programming (MIP) models using a matrix format. The logic satisfies the following requirements: flexible editing with symmetric operations by row and column, ease of use, editing of big models with good response time.

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Interactive Editing of Linear and Mixed Integer Programming Models

The Model Manager is a matrix editor which allows an interactive editing of Linear Programming (LP) and Mixed Integer Programming (MIP) models using a matrix format. The logic satisfies the following requirements: flexible editing with symmetric operations by row and column, ease of use, editing of big models with good response time.

To achieve good performances even with big models (> 100000 not-zero coefficients) the model representation is kept in virtual storage. The internal model representation aims to minimize the storage occupation, maintaining a high level of flexibility/symmetry of the model editing operators, but avoiding memory constraints. The model representation is based on three main structures:

1. The Names arrays (row array and column array) contain the items names type, matrix order chain, hashing table chain (for fast "by name" item retrieval) and pointers to the row/column entries in the appropriate Matrix Pool.

2. The Matrix Pools (Row Pool and Column Pool) are two separate super sparse matrix representations of the same matrix. Each pool is a set of "slots" containing all the matrix information related to a specific item (rows in Row Pool and columns in Column Pool). Each slot contains the address of the coefficient values and the index of the column (in Row Pool) or the row (in Column Pool) related to the coefficient entry. Bounds are considered a special row, Right Hand Si...