redhat man page for dorgr2

DORGR2(l)								 )								 DORGR2(l)

NAME
       DORGR2 - generate an m by n real matrix Q with orthonormal rows,

SYNOPSIS
       SUBROUTINE DORGR2( M, N, K, A, LDA, TAU, WORK, INFO )

	   INTEGER	  INFO, K, LDA, M, N

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

PURPOSE
       DORGR2 generates an m by n real matrix Q with orthonormal rows, which is defined as the last m rows of a product of k elementary reflectors
       of order n

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

       as returned by DGERQF.

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 (m-k+i)-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by
	       DGERQF in the last 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 DGERQF.

       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

LAPACK version 3.0						   15 June 2000 							 DORGR2(l)