Provided by: liblapack-doc_3.3.1-1_all bug

NAME

       LAPACK-3 - 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

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**T from the Left
                = 'R': apply H or H**T from the Right

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

        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 routine (version 3.3.1)             April 2011                            DLARZB(3lapack)