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Livre :
Expressions régulières,
Syntaxe et mise en oeuvre :

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

GNU/Linux

CentOS 4.8

i386

zpttrs(l)


ZPTTRS

ZPTTRS

NAME
SYNOPSIS
PURPOSE
ARGUMENTS

NAME

ZPTTRS - solve a tridiagonal system of the form A * X = B using the factorization A = U’*D*U or A = L*D*L’ computed by ZPTTRF

SYNOPSIS

SUBROUTINE ZPTTRS(

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

CHARACTER

UPLO

INTEGER

INFO, LDB, N, NRHS

DOUBLE

PRECISION D( * )

COMPLEX*16

B( LDB, * ), E( * )

PURPOSE

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

ARGUMENTS

UPLO (input) CHARACTER*1

Specifies the form of the factorization and whether the vector E is the superdiagonal of the upper bidiagonal factor U or the subdiagonal of the lower bidiagonal factor L. = ’U’: A = U’*D*U, E is the superdiagonal of U
= ’L’: A = L*D*L’, E is the subdiagonal of L

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) DOUBLE PRECISION array, dimension (N)

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

E (input) COMPLEX*16 array, dimension (N-1)

If UPLO = ’U’, the (n-1) superdiagonal elements of the unit bidiagonal factor U from the factorization A = U’*D*U. If UPLO = ’L’, the (n-1) subdiagonal elements of the unit bidiagonal factor L from the factorization A = L*D*L’.

B (input/output) DOUBLE PRECISION 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).

INFO (output) INTEGER

= 0: successful exit
< 0: if INFO = -k, the k-th argument had an illegal value



zpttrs(l)