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

zunglq(l)


ZUNGLQ

ZUNGLQ

NAME
SYNOPSIS
PURPOSE
ARGUMENTS

NAME

ZUNGLQ - generate an M-by-N complex matrix Q with orthonormal rows,

SYNOPSIS

SUBROUTINE ZUNGLQ(

M, N, K, A, LDA, TAU, WORK, LWORK, INFO )

INTEGER

INFO, K, LDA, LWORK, M, N

COMPLEX*16

A( LDA, * ), TAU( * ), WORK( * )

PURPOSE

ZUNGLQ generates an M-by-N complex 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 ZGELQF.

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) COMPLEX*16 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 ZGELQF 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) COMPLEX*16 array, dimension (K)

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

WORK (workspace/output) COMPLEX*16 array, dimension (LWORK)

On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

LWORK (input) INTEGER

The dimension of the array WORK. LWORK >= max(1,M). For optimum performance LWORK >= M*NB, where NB is the optimal blocksize.

If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA.

INFO (output) INTEGER

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



zunglq(l)