debian man page for pcpttrf

PCPTTRF(l)						   LAPACK routine (version 1.5) 						PCPTTRF(l)

NAME
       PCPTTRF	-  compute  a  Cholesky  factorization	of  an	N-by-N	complex  tridiagonal symmetric positive definite distributed matrix A(1:N,
       JA:JA+N-1)

SYNOPSIS
       SUBROUTINE PCPTTRF( N, D, E, JA, DESCA, AF, LAF, WORK, LWORK, INFO )

	   INTEGER	   INFO, JA, LAF, LWORK, N

	   INTEGER	   DESCA( * )

	   COMPLEX	   AF( * ), E( * ), WORK( * )

	   REAL 	   D( * )

PURPOSE
       PCPTTRF computes a Cholesky factorization  of  an  N-by-N  complex  tridiagonal	symmetric  positive  definite  distributed  matrix  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 PCPTTRS to solve linear systems.

       The factorization has the form

	       P A(1:N, JA:JA+N-1) P^T = U' D U  or

	       P A(1:N, JA:JA+N-1) P^T = L D L',

       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 							PCPTTRF(l)