Poster of Linux kernelThe best gift for a Linux geek
PDDBTRF

PDDBTRF

Section: LAPACK routine (version 1.5) (l) Updated: 12 May 1997
Local index Up
 

NAME

PDDBTRF - compute a LU factorization of an N-by-N real banded diagonally dominant-like distributed matrix with bandwidth BWL, BWU  

SYNOPSIS

SUBROUTINE PDDBTRF(
N, BWL, BWU, A, JA, DESCA, AF, LAF, WORK, LWORK, INFO )

    
INTEGER BWL, BWU, INFO, JA, LAF, LWORK, N

    
INTEGER DESCA( * )

    
DOUBLE PRECISION A( * ), AF( * ), WORK( * )
 

PURPOSE

PDDBTRF computes a LU factorization of an N-by-N real banded diagonally dominant-like distributed matrix with bandwidth BWL, BWU: A(1:N, JA:JA+N-1). Reordering is used to increase parallelism in the factorization. This reordering results in factors that are DIFFERENT from those produced by equivalent sequential codes. These factors cannot be used directly by users; however, they can be used in
subsequent calls to PDDBTRS to solve linear systems.

The factorization has the form


        P A(1:N, JA:JA+N-1) P^T = L U

where U is a banded upper triangular matrix and L is banded lower triangular, and P is a permutation matrix.


 

Index

NAME
SYNOPSIS
PURPOSE

This document was created by man2html, using the manual pages.
Time: 21:52:10 GMT, April 16, 2011