ZUNGTR(l)		LAPACK routine (version	1.1)		    ZUNGTR(l)

NAME
  ZUNGTR - generate a complex unitary matrix Q which is	defined	as the pro-
  duct of n-1 elementary reflectors of order N,	as returned by ZHETRD

SYNOPSIS

  SUBROUTINE ZUNGTR( UPLO, N, A, LDA, TAU, WORK, LWORK,	INFO )

      CHARACTER	     UPLO

      INTEGER	     INFO, LDA,	LWORK, N

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

PURPOSE
  ZUNGTR generates a complex unitary matrix Q which is defined as the product
  of n-1 elementary reflectors of order	N, as returned by ZHETRD:

  if UPLO = 'U', Q = H(n-1) . .	. H(2) H(1),

  if UPLO = 'L', Q = H(1) H(2) . . . H(n-1).

ARGUMENTS

  UPLO	  (input) CHARACTER*1
	  = 'U': Upper triangle	of A contains elementary reflectors from
	  ZHETRD; = 'L': Lower triangle	of A contains elementary reflectors
	  from ZHETRD.

  N	  (input) INTEGER
	  The order of the matrix Q. N >= 0.

  A	  (input/output) COMPLEX*16 array, dimension (LDA,N)
	  On entry, the	vectors	which define the elementary reflectors,	as
	  returned by ZHETRD.  On exit,	the N-by-N unitary matrix Q.

  LDA	  (input) INTEGER
	  The leading dimension	of the array A.	LDA >= N.

  TAU	  (input) COMPLEX*16 array, dimension (N-1)
	  TAU(i) must contain the scalar factor	of the elementary reflector
	  H(i),	as returned by ZHETRD.

  WORK	  (workspace) COMPLEX*16 array,	dimension (LWORK)
	  On exit, if INFO = 0,	WORK(1)	returns	the optimal LWORK.

  LWORK	  (input) INTEGER
	  The dimension	of the array WORK. LWORK >= N-1.  For optimum perfor-
	  mance	LWORK >= (N-1)*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


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