SGEQLF(l)		LAPACK routine (version	1.1)		    SGEQLF(l)

NAME
  SGEQLF - compute a QL	factorization of a real	M-by-N matrix A

SYNOPSIS

  SUBROUTINE SGEQLF( M,	N, A, LDA, TAU,	WORK, LWORK, INFO )

      INTEGER	     INFO, LDA,	LWORK, M, N

      REAL	     A(	LDA, * ), TAU( * ), WORK( LWORK	)

PURPOSE
  SGEQLF computes a QL factorization of	a real M-by-N matrix A:	A = Q *	L.

ARGUMENTS

  M	  (input) INTEGER
	  The number of	rows of	the matrix A.  M >= 0.

  N	  (input) INTEGER
	  The number of	columns	of the matrix A.  N >= 0.

  A	  (input/output) REAL array, dimension (LDA,N)
	  On entry, the	M-by-N matrix A.  On exit, if m	>= n, the lower	tri-
	  angle	of the subarray	A(m-n+1:m,1:n) contains	the N-by-N lower tri-
	  angular matrix L; if m <= n, the elements on and below the (n-m)-th
	  superdiagonal	contain	the M-by-N lower trapezoidal matrix L; the
	  remaining elements, with the array TAU, represent the	orthogonal
	  matrix Q as a	product	of elementary reflectors (see Further
	  Details).  LDA     (input) INTEGER The leading dimension of the
	  array	A.  LDA	>= max(1,M).

  TAU	  (output) REAL	array, dimension (min(M,N))
	  The scalar factors of	the elementary reflectors (see Further
	  Details).

  WORK	  (workspace) REAL 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,N).	For optimum
	  performance LWORK >= N*NB, where NB is the optimal blocksize.

  INFO	  (output) INTEGER
	  = 0:	successful exit
	  < 0:	if INFO	= -i, the i-th argument	had an illegal value

FURTHER	DETAILS
  The matrix Q is represented as a product of elementary reflectors

     Q = H(k) .	. . H(2) H(1), where k = min(m,n).

  Each H(i) has	the form

     H(i) = I -	tau * v	* v'

  where	tau is a real scalar, and v is a real vector with
  v(m-k+i+1:m) = 0 and v(m-k+i)	= 1; v(1:m-k+i-1) is stored on exit in
  A(1:m-k+i-1,n-k+i), and tau in TAU(i).


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