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dlarfb.f(3)			    LAPACK			   dlarfb.f(3)

NAME
       dlarfb.f -

SYNOPSIS
   Functions/Subroutines
       subroutine dlarfb (SIDE, TRANS, DIRECT, STOREV, M, N, K, V, LDV, T,
	   LDT, C, LDC, WORK, LDWORK)
	   DLARFB applies a block reflector or its transpose to a general
	   rectangular matrix.

Function/Subroutine Documentation
   subroutine dlarfb (characterSIDE, characterTRANS, characterDIRECT,
       characterSTOREV, integerM, integerN, integerK, double precision,
       dimension( ldv, * )V, integerLDV, double precision, dimension( ldt, *
       )T, integerLDT, double precision, dimension( ldc, * )C, integerLDC,
       double precision, dimension( ldwork, * )WORK, integerLDWORK)
       DLARFB applies a block reflector or its transpose to a general
       rectangular matrix.

       Purpose:

	    DLARFB applies a real block reflector H or its transpose H**T to a
	    real m by n matrix C, from either the left or the right.

       Parameters:
	   SIDE

		     SIDE is CHARACTER*1
		     = 'L': apply H or H**T from the Left
		     = 'R': apply H or H**T from the Right

	   TRANS

		     TRANS is CHARACTER*1
		     = 'N': apply H (No transpose)
		     = 'T': apply H**T (Transpose)

	   DIRECT

		     DIRECT is CHARACTER*1
		     Indicates how H is formed from a product of elementary
		     reflectors
		     = 'F': H = H(1) H(2) . . . H(k) (Forward)
		     = 'B': H = H(k) . . . H(2) H(1) (Backward)

	   STOREV

		     STOREV is CHARACTER*1
		     Indicates how the vectors which define the elementary
		     reflectors are stored:
		     = 'C': Columnwise
		     = 'R': Rowwise

	   M

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

	   N

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

	   K

		     K is INTEGER
		     The order of the matrix T (= the number of elementary
		     reflectors whose product defines the block reflector).

	   V

		     V is DOUBLE PRECISION array, dimension
					   (LDV,K) if STOREV = 'C'
					   (LDV,M) if STOREV = 'R' and SIDE = 'L'
					   (LDV,N) if STOREV = 'R' and SIDE = 'R'
		     The matrix V. See Further Details.

	   LDV

		     LDV is INTEGER
		     The leading dimension of the array V.
		     If STOREV = 'C' and SIDE = 'L', LDV >= max(1,M);
		     if STOREV = 'C' and SIDE = 'R', LDV >= max(1,N);
		     if STOREV = 'R', LDV >= K.

	   T

		     T is DOUBLE PRECISION array, dimension (LDT,K)
		     The triangular k by k matrix T in the representation of the
		     block reflector.

	   LDT

		     LDT is INTEGER
		     The leading dimension of the array T. LDT >= K.

	   C

		     C is DOUBLE PRECISION array, dimension (LDC,N)
		     On entry, the m by n matrix C.
		     On exit, C is overwritten by H*C or H**T*C or C*H or C*H**T.

	   LDC

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

	   WORK

		     WORK is DOUBLE PRECISION array, dimension (LDWORK,K)

	   LDWORK

		     LDWORK is INTEGER
		     The leading dimension of the array WORK.
		     If SIDE = 'L', LDWORK >= max(1,N);
		     if SIDE = 'R', LDWORK >= max(1,M).

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   June 2013

       Further Details:

	     The shape of the matrix V and the storage of the vectors which define
	     the H(i) is best illustrated by the following example with n = 5 and
	     k = 3. The elements equal to 1 are not stored; the corresponding
	     array elements are modified but restored on exit. The rest of the
	     array is not used.

	     DIRECT = 'F' and STOREV = 'C':	    DIRECT = 'F' and STOREV = 'R':

			  V = (	 1	 )		   V = (  1 v1 v1 v1 v1 )
			      ( v1  1	 )		       (     1 v2 v2 v2 )
			      ( v1 v2  1 )		       (	1 v3 v3 )
			      ( v1 v2 v3 )
			      ( v1 v2 v3 )

	     DIRECT = 'B' and STOREV = 'C':	    DIRECT = 'B' and STOREV = 'R':

			  V = ( v1 v2 v3 )		   V = ( v1 v1	1	)
			      ( v1 v2 v3 )		       ( v2 v2 v2  1	)
			      (	 1 v2 v3 )		       ( v3 v3 v3 v3  1 )
			      (	    1 v3 )
			      (	       1 )

       Definition at line 195 of file dlarfb.f.

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

Version 3.4.2			Sat Nov 16 2013			   dlarfb.f(3)
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