dlarfb(3F)

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).