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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
	dorgl2(l)

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DORGL2

NAME
SYNOPSIS
PURPOSE
ARGUMENTS

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NAME

DORGL2 - generate an m by n real matrix Q with orthonormal rows,

SYNOPSIS

	SUBROUTINE DORGL2(		M, N, K, A, LDA, TAU, WORK, INFO )
	INTEGER		INFO, K, LDA, M, N
	DOUBLE		PRECISION A( LDA, * ), TAU( * ), WORK( * )

PURPOSE

DORGL2 generates an m by n real matrix Q with orthonormal rows, which is defined as the first m rows of a product of k elementary reflectors of order n

Q = H(k) . . . H(2) H(1)

as returned by DGELQF.

ARGUMENTS

M (input) INTEGER

The number of rows of the matrix Q. M >= 0.

N (input) INTEGER

The number of columns of the matrix Q. N >= M.

K (input) INTEGER

The number of elementary reflectors whose product defines the matrix Q. M >= K >= 0.

A (input/output) DOUBLE PRECISION array, dimension (LDA,N)

On entry, the i-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by DGELQF in the first k rows of its array argument A. On exit, the m-by-n matrix Q.

LDA (input) INTEGER

The first dimension of the array A. LDA >= max(1,M).

TAU (input) DOUBLE PRECISION array, dimension (K)

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

WORK (workspace) DOUBLE PRECISION array, dimension (M)
INFO (output) INTEGER

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

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dorgl2(l)