Provided by: scalapack-doc_1.5-10_all
NAME
PZDTTRF - 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 PZDTTRF( N, DL, D, DU, JA, DESCA, AF, LAF, WORK, LWORK, INFO ) INTEGER INFO, JA, LAF, LWORK, N INTEGER DESCA( * ) COMPLEX*16 AF( * ), D( * ), DL( * ), DU( * ), WORK( * )
PURPOSE
PZDTTRF 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 PZDTTRS 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.