dlarz(l) [redhat man page]

DLARZ(l)								 )								  DLARZ(l)

NAME

       DLARZ - applie a real elementary reflector H to a real M-by-N matrix C, from either the left or the right

SYNOPSIS

       SUBROUTINE DLARZ( SIDE, M, N, L, V, INCV, TAU, C, LDC, WORK )

	   CHARACTER	 SIDE

	   INTEGER	 INCV, L, LDC, M, N

	   DOUBLE	 PRECISION TAU

	   DOUBLE	 PRECISION C( LDC, * ), V( * ), WORK( * )

PURPOSE

       DLARZ applies a real elementary reflector H to a real M-by-N matrix C, from either the left or the right. H is represented in the form

	     H = I - tau * v * v'

       where tau is a real scalar and v is a real vector.

       If tau = 0, then H is taken to be the unit matrix.

       H is a product of k elementary reflectors as returned by DTZRZF.

ARGUMENTS

       SIDE    (input) CHARACTER*1
	       = 'L': form  H * C
	       = 'R': form  C * H

       M       (input) INTEGER
	       The number of rows of the matrix C.

       N       (input) INTEGER
	       The number of columns of the matrix C.

       L       (input) INTEGER
	       The  number  of	entries of the vector V containing the meaningful part of the Householder vectors.  If SIDE = 'L', M >= L >= 0, if
	       SIDE = 'R', N >= L >= 0.

       V       (input) DOUBLE PRECISION array, dimension (1+(L-1)*abs(INCV))
	       The vector v in the representation of H as returned by DTZRZF. V is not used if TAU = 0.

       INCV    (input) INTEGER
	       The increment between elements of v. INCV <> 0.

       TAU     (input) DOUBLE PRECISION
	       The value tau in the representation of H.

       C       (input/output) DOUBLE PRECISION array, dimension (LDC,N)
	       On entry, the M-by-N matrix C.  On exit, C is overwritten by the matrix H * C if SIDE = 'L', or C * H if SIDE = 'R'.

       LDC     (input) INTEGER
	       The leading dimension of the array C. LDC >= max(1,M).

       WORK    (workspace) DOUBLE PRECISION array, dimension
	       (N) if SIDE = 'L' or (M) if SIDE = 'R'

FURTHER DETAILS

       Based on contributions by
	 A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA

LAPACK version 3.0						   15 June 2000 							  DLARZ(l)

dlarz.f(3)							      LAPACK								dlarz.f(3)

NAME

       dlarz.f -

SYNOPSIS

   Functions/Subroutines
       subroutine dlarz (SIDE, M, N, L, V, INCV, TAU, C, LDC, WORK)
	   DLARZ applies an elementary reflector (as returned by stzrzf) to a general matrix.

Function/Subroutine Documentation
   subroutine dlarz (characterSIDE, integerM, integerN, integerL, double precision, dimension( * )V, integerINCV, double precisionTAU, double
       precision, dimension( ldc, * )C, integerLDC, double precision, dimension( * )WORK)
       DLARZ applies an elementary reflector (as returned by stzrzf) to a general matrix.

       Purpose:

	    DLARZ applies a real elementary reflector H to a real M-by-N
	    matrix C, from either the left or the right. H is represented in the
	    form

		  H = I - tau * v * v**T

	    where tau is a real scalar and v is a real vector.

	    If tau = 0, then H is taken to be the unit matrix.

	    H is a product of k elementary reflectors as returned by DTZRZF.

       Parameters:
	   SIDE

		     SIDE is CHARACTER*1
		     = 'L': form  H * C
		     = 'R': form  C * H

	   M

		     M is INTEGER
		     The number of rows of the matrix C.

	   N

		     N is INTEGER
		     The number of columns of the matrix C.

	   L

		     L is INTEGER
		     The number of entries of the vector V containing
		     the meaningful part of the Householder vectors.
		     If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0.

	   V

		     V is DOUBLE PRECISION array, dimension (1+(L-1)*abs(INCV))
		     The vector v in the representation of H as returned by
		     DTZRZF. V is not used if TAU = 0.

	   INCV

		     INCV is INTEGER
		     The increment between elements of v. INCV <> 0.

	   TAU

		     TAU is DOUBLE PRECISION
		     The value tau in the representation of H.

	   C

		     C is DOUBLE PRECISION array, dimension (LDC,N)
		     On entry, the M-by-N matrix C.
		     On exit, C is overwritten by the matrix H * C if SIDE = 'L',
		     or C * H if SIDE = 'R'.

	   LDC

		     LDC is INTEGER
		     The leading dimension of the array C. LDC >= max(1,M).

	   WORK

		     WORK is DOUBLE PRECISION array, dimension
				    (N) if SIDE = 'L'
				 or (M) if SIDE = 'R'

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   September 2012

       Contributors:
	   A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA

       Further Details:

       Definition at line 146 of file dlarz.f.

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

Version 3.4.2							  Tue Sep 25 2012							dlarz.f(3)