CXML
        	    
LAPACK version 3.0
dorgql(3)

PURPOSE
  DORGQL - generate an M-by-N real matrix Q with orthonormal columns,

SYNTAX
  SUBROUTINE DORGQL( M, N, K, A, LDA, TAU, WORK, LWORK, INFO )

      INTEGER	     INFO, K, LDA, LWORK, M, N

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

DESCRIPTION
  DORGQL 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/output) DOUBLE PRECISION 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.

	  If LWORK = -1, then a workspace query is assumed; the routine only
	  calculates the optimal size of the WORK array, returns this value
	  as the first entry of the WORK array, and no error message related
	  to LWORK is issued by XERBLA.

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