Accession Number : ADA139184

Title :   A Parallel QR Method Using Fast Givens' Rotations.

Descriptive Note : Research rept.,

Corporate Author : YALE UNIV NEW HAVEN CT DEPT OF COMPUTER SCIENCE

Personal Author(s) : Ipsen,I C F

PDF Url : ADA139184

Report Date : Jan 1984

Pagination or Media Count : 17

Abstract : Given a prescribed order in which to introduce zeroes, and constraints on the architecture it is shown how to develop a parallel QR factorization based on fast Givens' rotations for a rectangular array of processors, suitable to VLSI implementation. Unlike designs based on standard Givens' transformations, the present one requires no square root computations. Assuming each processor performs the elementary operations (+,*,/), less than O(w sub 2) processors can achieve the decomposition of a w-banded, order n matrix in time O(n). Application is made to a variant of Bareiss' G-Algorithm for the solution of weighted multiple linear least squares problems. Given k different right hand side vectors, (w sub 2) processors compute the factorization in O(n + k) steps. (Author)

Descriptors :   *Numerical methods and procedures, *Factor analysis, *Parallel processors, Least squares method, Algorithms, Matrices(Mathematics), Decomposition, Input output processing, Transformations(Mathematics)

Subject Categories : Statistics and Probability
      Computer Hardware

Distribution Statement : APPROVED FOR PUBLIC RELEASE