Accession Number : ADA190590

Title :   A New Block Solver for Large, Full, Unsymmetric, Complex Systems of Linear Algebraic Equations.

Descriptive Note : Final rept.,

Corporate Author : DAVID TAYLOR RESEARCH CENTER BETHESDA MD

Personal Author(s) : Schroeder, Erwin A

PDF Url : ADA190590

Report Date : Feb 1988

Pagination or Media Count : 27

Abstract : A new block solver, OCSOLVE, for large, full, unsymmetric systems of algebraic equations with complex-valued coefficients has been developed. Although OCSOLVE was developed for use with the finite element program NASTRAN, it is designed to be easily adapted for other applications. This new solver was developed because NASTRAN's solver was not designed to solve full, unsymmetric systems efficiently; it reduced the time required to solve such a system of 500 equations with complex-valued coefficients to about 5% of the time required by the equation solver in NASTRAN. The solver is easily modified to use double precision complex arithmetic on computers on which it is available. With somewhat more effort it could be modified to solve systems of equations having real-valued coefficients. Several features distinguish this linear equation solver from previous solvers. It automatically determines the dimensions of the blocks of coefficients and blocks of right-hand side vectors and avoids the need for adding extra equations by providing for blocks of more than one size. It accepts columns of the coefficient matrix and columns of the right-hand side vectors from a sequential file and returns the columns of solution vectors on a sequential file. The program OCSOLVE will solve with one call, a linear system having multiple right-hand sides. It will solve a system of linear equations if a specified minimum number of words are provided for storing the blocks; however, the more memory provided, and hence the larger the blocks, the more efficient the solution will be.

Descriptors :   *LINEAR ALGEBRAIC EQUATIONS, *LINEAR PROGRAMMING, *SUBROUTINES, ARITHMETIC, COEFFICIENTS, COMPUTERS, FINITE ELEMENT ANALYSIS, LINEAR SYSTEMS, PRECISION, SIZES(DIMENSIONS), PROBLEM SOLVING, FORTRAN

Subject Categories : Operations Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE