Flashnux

GNU/Linux man pages

Livre :
Expressions régulières,
Syntaxe et mise en oeuvre :

ISBN : 978-2-7460-9712-4
EAN : 9782746097124
(Editions ENI)

GNU/Linux

CentOS 4.8

i386

sptts2(l)


SPTTS2

SPTTS2

NAME
SYNOPSIS
PURPOSE
ARGUMENTS

NAME

SPTTS2 - solve a tridiagonal system of the form A * X = B using the L*D*L’ factorization of A computed by SPTTRF

SYNOPSIS

SUBROUTINE SPTTS2(

N, NRHS, D, E, B, LDB )

INTEGER

LDB, N, NRHS

REAL

B( LDB, * ), D( * ), E( * )

PURPOSE

SPTTS2 solves a tridiagonal system of the form A * X = B using the L*D*L’ factorization of A computed by SPTTRF. D is a diagonal matrix specified in the vector D, L is a unit bidiagonal matrix whose subdiagonal is specified in the vector E, and X and B are N by NRHS matrices.

ARGUMENTS

N (input) INTEGER

The order of the tridiagonal matrix A. N >= 0.

NRHS (input) INTEGER

The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.

D (input) REAL array, dimension (N)

The n diagonal elements of the diagonal matrix D from the L*D*L’ factorization of A.

E (input) REAL array, dimension (N-1)

The (n-1) subdiagonal elements of the unit bidiagonal factor L from the L*D*L’ factorization of A. E can also be regarded as the superdiagonal of the unit bidiagonal factor U from the factorization A = U’*D*U.

B (input/output) REAL array, dimension (LDB,NRHS)

On entry, the right hand side vectors B for the system of linear equations. On exit, the solution vectors, X.

LDB (input) INTEGER

The leading dimension of the array B. LDB >= max(1,N).



sptts2(l)