cunghr.f(3)							      LAPACK							       cunghr.f(3)

NAME

       cunghr.f -

SYNOPSIS

   Functions/Subroutines
       subroutine cunghr (N, ILO, IHI, A, LDA, TAU, WORK, LWORK, INFO)
	   CUNGHR

Function/Subroutine Documentation
   subroutine cunghr (integerN, integerILO, integerIHI, complex, dimension( lda, * )A, integerLDA, complex, dimension( * )TAU, complex, dimension(
       * )WORK, integerLWORK, integerINFO)
       CUNGHR

       Purpose:

	    CUNGHR generates a complex unitary matrix Q which is defined as the
	    product of IHI-ILO elementary reflectors of order N, as returned by
	    CGEHRD:

	    Q = H(ilo) H(ilo+1) . . . H(ihi-1).

       Parameters:
	   N

		     N is INTEGER
		     The order of the matrix Q. N >= 0.

	   ILO

		     ILO is INTEGER

	   IHI

		     IHI is INTEGER

		     ILO and IHI must have the same values as in the previous call
		     of CGEHRD. Q is equal to the unit matrix except in the
		     submatrix Q(ilo+1:ihi,ilo+1:ihi).
		     1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.

	   A

		     A is COMPLEX array, dimension (LDA,N)
		     On entry, the vectors which define the elementary reflectors,
		     as returned by CGEHRD.
		     On exit, the N-by-N unitary matrix Q.

	   LDA

		     LDA is INTEGER
		     The leading dimension of the array A. LDA >= max(1,N).

	   TAU

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

	   WORK

		     WORK is COMPLEX array, dimension (MAX(1,LWORK))
		     On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

	   LWORK

		     LWORK is INTEGER
		     The dimension of the array WORK. LWORK >= IHI-ILO.
		     For optimum performance LWORK >= (IHI-ILO)*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

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

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   November 2011

       Definition at line 127 of file cunghr.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.1							  Sun May 26 2013						       cunghr.f(3)