redhat man page for zung2l

ZUNG2L(l)								 )								 ZUNG2L(l)

NAME
       ZUNG2L - generate an m by n complex matrix Q with orthonormal columns,

SYNOPSIS
       SUBROUTINE ZUNG2L( M, N, K, A, LDA, TAU, WORK, INFO )

	   INTEGER	  INFO, K, LDA, M, N

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

PURPOSE
       ZUNG2L  generates  an m by n complex 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 ZGEQLF.

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) COMPLEX*16 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 ZGEQLF 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) COMPLEX*16 array, dimension (K)
	       TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by ZGEQLF.

       WORK    (workspace) COMPLEX*16 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 							 ZUNG2L(l)