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.