dlarfb(l) [redhat man page]

DLARFB(l)								 )								 DLARFB(l)

NAME

       DLARFB - applie a real block reflector H or its transpose H' to a real m by n matrix C, from either the left or the right

SYNOPSIS

       SUBROUTINE DLARFB( SIDE, TRANS, DIRECT, STOREV, M, N, K, V, LDV, T, LDT, C, LDC, WORK, LDWORK )

	   CHARACTER	  DIRECT, SIDE, STOREV, TRANS

	   INTEGER	  K, LDC, LDT, LDV, LDWORK, M, N

	   DOUBLE	  PRECISION C( LDC, * ), T( LDT, * ), V( LDV, * ), WORK( LDWORK, * )

PURPOSE

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

ARGUMENTS

       SIDE    (input) CHARACTER*1
	       = 'L': apply H or H' from the Left
	       = 'R': apply H or H' from the Right

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

       DIRECT  (input) 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  (input) CHARACTER*1
	       Indicates how the vectors which define the elementary reflectors are stored:
	       = 'C': Columnwise
	       = 'R': Rowwise

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

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

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

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

       LDT     (input) INTEGER
	       The leading dimension of the array T. LDT >= K.

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

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

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

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

LAPACK version 3.0						   15 June 2000 							 DLARFB(l)

DLARZB(l)								 )								 DLARZB(l)

NAME

       DLARZB - applie a real block reflector H or its transpose H**T to a real distributed M-by-N C from the left or the right

SYNOPSIS

       SUBROUTINE DLARZB( SIDE, TRANS, DIRECT, STOREV, M, N, K, L, V, LDV, T, LDT, C, LDC, WORK, LDWORK )

	   CHARACTER	  DIRECT, SIDE, STOREV, TRANS

	   INTEGER	  K, L, LDC, LDT, LDV, LDWORK, M, N

	   DOUBLE	  PRECISION C( LDC, * ), T( LDT, * ), V( LDV, * ), WORK( LDWORK, * )

PURPOSE

       DLARZB  applies	a real block reflector H or its transpose H**T to a real distributed M-by-N C from the left or the right.  Currently, only
       STOREV = 'R' and DIRECT = 'B' are supported.

ARGUMENTS

       SIDE    (input) CHARACTER*1
	       = 'L': apply H or H' from the Left
	       = 'R': apply H or H' from the Right

       TRANS   (input) CHARACTER*1
	       = 'N': apply H (No transpose)
	       = 'C': apply H' (Transpose)

       DIRECT  (input) CHARACTER*1
	       Indicates how H is formed from a product of elementary reflectors = 'F': H = H(1) H(2) . . . H(k) (Forward, not supported yet)
	       = 'B': H = H(k) . . . H(2) H(1) (Backward)

       STOREV  (input) CHARACTER*1
	       Indicates how the vectors which define the elementary reflectors are stored:
	       = 'C': Columnwise			(not supported yet)
	       = 'R': Rowwise

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

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

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

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

       V       (input) DOUBLE PRECISION array, dimension (LDV,NV).
	       If STOREV = 'C', NV = K; if STOREV = 'R', NV = L.

       LDV     (input) INTEGER
	       The leading dimension of the array V.  If STOREV = 'C', LDV >= L; if STOREV = 'R', LDV >= K.

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

       LDT     (input) INTEGER
	       The leading dimension of the array T. LDT >= K.

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

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

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

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

FURTHER DETAILS

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

LAPACK version 3.0						   15 June 2000 							 DLARZB(l)