redhat man page for dorg2l

DORG2L(l)								 )								 DORG2L(l)

NAME
       DORG2L - generate an m by n real matrix Q with orthonormal columns,

SYNOPSIS
       SUBROUTINE DORG2L( M, N, K, A, LDA, TAU, WORK, INFO )

	   INTEGER	  INFO, K, LDA, M, N

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

PURPOSE
       DORG2L  generates  an  m  by  n real matrix Q with orthonormal columns, which is defined as the last n columns of a product of k elementary
       reflectors of order m

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

       as returned by DGEQLF.

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. M >= N >= 0.

       K       (input) INTEGER
	       The number of elementary reflectors whose product defines the matrix Q. N >= K >= 0.

       A       (input/output) DOUBLE PRECISION array, dimension (LDA,N)
	       On entry, the (n-k+i)-th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned
	       by DGEQLF in the last k columns 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 DGEQLF.

       WORK    (workspace) DOUBLE PRECISION array, dimension (N)

       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 							 DORG2L(l)