Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
PDDTTRF(l)			       )			    PDDTTRF(l)

NAME
       PDDTTRF	- compute a LU factorization of	an N-by-N real tridiagonal di-
       agonally	dominant-like distributed matrix A(1:N,	JA:JA+N-1)

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

	   INTEGER	   INFO, JA, LAF, LWORK, N

	   INTEGER	   DESCA( * )

	   DOUBLE	   PRECISION  AF( * ), D( * ), DL( * ),	DU( * ), WORK(
			   * )

PURPOSE
       PDDTTRF computes	a LU factorization of an N-by-N	real tridiagonal diag-
       onally  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;  how-
       ever, they can be used in
       subsequent calls	to PDDTTRS 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.

ScaLAPACK version 1.7		13 August 2001			    PDDTTRF(l)

NAME | SYNOPSIS | PURPOSE

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=pddttrf&manpath=FreeBSD+12.0-RELEASE+and+Ports>

home | help