redhat man page for zungr2

ZUNGR2(l)								 )								 ZUNGR2(l)

NAME
       ZUNGR2 - generate an m by n complex matrix Q with orthonormal rows,

SYNOPSIS
       SUBROUTINE ZUNGR2( M, N, K, A, LDA, TAU, WORK, INFO )

	   INTEGER	  INFO, K, LDA, M, N

	   COMPLEX*16	  A( LDA, * ), TAU( * ), WORK( * )

PURPOSE
       ZUNGR2 generates an m by n complex matrix Q with orthonormal rows, which is defined as the last m rows of a product of k elementary reflec-
       tors of order n

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

       as returned by ZGERQF.

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 (m-k+i)-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by
	       ZGERQF 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) COMPLEX*16 array, dimension (K)
	       TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGERQF.

       WORK    (workspace) COMPLEX*16 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 							 ZUNGR2(l)