redhat man page for dorglq

DORGLQ(l)								 )								 DORGLQ(l)

NAME
       DORGLQ - generate an M-by-N real matrix Q with orthonormal rows,

SYNOPSIS
       SUBROUTINE DORGLQ( M, N, K, A, LDA, TAU, WORK, LWORK, INFO )

	   INTEGER	  INFO, K, LDA, LWORK, M, N

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

PURPOSE
       DORGLQ  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 reflec-
       tors 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/output) DOUBLE PRECISION 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

LAPACK version 3.0						   15 June 2000 							 DORGLQ(l)