====================================================================
dlarfb examples
====================================================================

====================================================================
Man Page Details
====================================================================

NAME
       DLARFB  - 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).

