pddttrf(3) debian man page | unix.com

PDDTTRF(l)						   LAPACK routine (version 1.5) 						PDDTTRF(l)

NAME
       PDDTTRF - compute a LU factorization of an N-by-N real tridiagonal diagonally dominant-like distributed matrix A(1:N, JA:JA+N-1)

SYNOPSIS
       SUBROUTINE PDDTTRF( N, DL, D, DU, JA, DESCA, AF, LAF, WORK, LWORK, INFO )

	   INTEGER	   INFO, JA, LAF, LWORK, N

	   INTEGER	   DESCA( * )

	   DOUBLE	   PRECISION AF( * ), D( * ), DL( * ), DU( * ), WORK( * )

PURPOSE
       PDDTTRF	computes a LU factorization of an N-by-N real tridiagonal diagonally dominant-like distributed matrix A(1:N, JA:JA+N-1).  Reorder-
       ing 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 PDDTTRS 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 tridiagonal upper triangular matrix and L is tridiagonal lower triangular, and P is a permutation matrix.

LAPACK version 1.5						    12 May 1997 							PDDTTRF(l)