Poster of Linux kernelThe best gift for a Linux geek
PZPTTRF

PZPTTRF

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

NAME

PZPTTRF - 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 PZPTTRF(
N, D, E, JA, DESCA, AF, LAF, WORK, LWORK, INFO )

    
INTEGER INFO, JA, LAF, LWORK, N

    
INTEGER DESCA( * )

    
COMPLEX*16 AF( * ), E( * ), WORK( * )

    
DOUBLE PRECISION D( * )
 

PURPOSE

PZPTTRF 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 PZPTTRS 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.


 

Index

NAME
SYNOPSIS
PURPOSE

This document was created by man2html, using the manual pages.
Time: 21:53:25 GMT, April 16, 2011