psdbtrf(3) debian man page | unix.com

PSDBTRF(l)						   LAPACK routine (version 1.5) 						PSDBTRF(l)

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

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

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

	   INTEGER	   DESCA( * )

	   REAL 	   A( * ), AF( * ), WORK( * )

PURPOSE
       PSDBTRF	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 PSDBTRS 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.

LAPACK version 1.5						    12 May 1997 							PSDBTRF(l)