bionic (3) pcdttrf.3.gz

NAME

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

SYNOPSIS

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

           INTEGER         INFO, JA, LAF, LWORK, N

           INTEGER         DESCA( * )

           COMPLEX         AF( * ), D( * ), DL( * ), DU( * ), WORK( * )

PURPOSE

       PCDTTRF computes a LU factorization of an N-by-N complex tridiagonal diagonally dominant-like 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 PCDTTRS 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.