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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
	sopgtr(l)

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SOPGTR

NAME
SYNOPSIS
PURPOSE
ARGUMENTS

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NAME

SOPGTR - generate a real orthogonal matrix Q which is defined as the product of n-1 elementary reflectors H(i) of order n, as returned by SSPTRD using packed storage

SYNOPSIS

	SUBROUTINE SOPGTR(		UPLO, N, AP, TAU, Q, LDQ, WORK, INFO )
	CHARACTER		UPLO
	INTEGER		INFO, LDQ, N
	REAL		AP( * ), Q( LDQ, * ), TAU( * ), WORK( * )

PURPOSE

SOPGTR generates a real orthogonal matrix Q which is defined as the product of n-1 elementary reflectors H(i) of order n, as returned by SSPTRD using packed storage: if UPLO = ’U’, Q = H(n-1) . . . H(2) H(1),

if UPLO = ’L’, Q = H(1) H(2) . . . H(n-1).

ARGUMENTS

UPLO (input) CHARACTER*1

= ’U’: Upper triangular packed storage used in previous call to SSPTRD; = ’L’: Lower triangular packed storage used in previous call to SSPTRD.

N (input) INTEGER

The order of the matrix Q. N >= 0.

AP (input) REAL array, dimension (N*(N+1)/2)

The vectors which define the elementary reflectors, as returned by SSPTRD.

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

TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by SSPTRD.

Q (output) REAL array, dimension (LDQ,N)

The N-by-N orthogonal matrix Q.

LDQ (input) INTEGER

The leading dimension of the array Q. LDQ >= max(1,N).

WORK (workspace) REAL array, dimension (N-1)
INFO (output) INTEGER

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

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sopgtr(l)