PCDBTRF(l) ) PCDBTRF(l)NAME
PCDBTRF - compute a LU factorization of an N-by-N complex banded diago‐
nally dominant-like distributed matrix with bandwidth BWL, BWU
SYNOPSIS
SUBROUTINE PCDBTRF( N, BWL, BWU, A, JA, DESCA, AF, LAF, WORK, LWORK,
INFO )
INTEGER BWL, BWU, INFO, JA, LAF, LWORK, N
INTEGER DESCA( * )
COMPLEX A( * ), AF( * ), WORK( * )
PURPOSE
PCDBTRF computes a LU factorization of an N-by-N complex banded diago‐
nally dominant-like distributed matrix with bandwidth BWL, BWU: A(1:N,
JA:JA+N-1). Reordering is used to increase parallelism in the factor‐
ization. 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 PCDBTRS 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 banded upper triangular matrix and L is banded lower tri‐
angular, and P is a permutation matrix.
ScaLAPACK version 1.7 13 August 2001 PCDBTRF(l)
