1CLARZB(1)                LAPACK routine (version 3.2)                CLARZB(1)
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NAME

6       CLARZB - applies a complex block reflector H or its transpose H**H to a
7       complex distributed M-by-N C from the left or the right
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SYNOPSIS

10       SUBROUTINE CLARZB( SIDE, TRANS, DIRECT, STOREV, M, N, K, L, V, LDV,  T,
11                          LDT, C, LDC, WORK, LDWORK )
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13           CHARACTER      DIRECT, SIDE, STOREV, TRANS
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15           INTEGER        K, L, LDC, LDT, LDV, LDWORK, M, N
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17           COMPLEX        C( LDC, * ), T( LDT, * ), V( LDV, * ), WORK( LDWORK,
18                          * )
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PURPOSE

21       CLARZB applies a complex block reflector H or its transpose H**H  to  a
22       complex  distributed  M-by-N  C from the left or the right.  Currently,
23       only STOREV = 'R' and DIRECT = 'B' are supported.
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ARGUMENTS

26       SIDE    (input) CHARACTER*1
27               = 'L': apply H or H' from the Left
28               = 'R': apply H or H' from the Right
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30       TRANS   (input) CHARACTER*1
31               = 'N': apply H (No transpose)
32               = 'C': apply H' (Conjugate transpose)
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34       DIRECT  (input) CHARACTER*1
35               Indicates how H is formed from a product of elementary  reflec‐
36               tors  =  'F':  H = H(1) H(2) . . . H(k) (Forward, not supported
37               yet)
38               = 'B': H = H(k) . . . H(2) H(1) (Backward)
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40       STOREV  (input) CHARACTER*1
41               Indicates how the vectors which define the  elementary  reflec‐
42               tors are stored:
43               = 'C': Columnwise                        (not supported yet)
44               = 'R': Rowwise
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46       M       (input) INTEGER
47               The number of rows of the matrix C.
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49       N       (input) INTEGER
50               The number of columns of the matrix C.
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52       K       (input) INTEGER
53               The  order  of the matrix T (= the number of elementary reflec‐
54               tors whose product defines the block reflector).
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56       L       (input) INTEGER
57               The number of columns of the matrix V containing the meaningful
58               part  of  the Householder reflectors.  If SIDE = 'L', M >= L >=
59               0, if SIDE = 'R', N >= L >= 0.
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61       V       (input) COMPLEX array, dimension (LDV,NV).
62               If STOREV = 'C', NV = K; if STOREV = 'R', NV = L.
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64       LDV     (input) INTEGER
65               The leading dimension of the array V.  If STOREV = 'C', LDV  >=
66               L; if STOREV = 'R', LDV >= K.
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68       T       (input) COMPLEX array, dimension (LDT,K)
69               The  triangular  K-by-K  matrix  T in the representation of the
70               block reflector.
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72       LDT     (input) INTEGER
73               The leading dimension of the array T. LDT >= K.
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75       C       (input/output) COMPLEX array, dimension (LDC,N)
76               On entry, the M-by-N matrix C.  On exit, C  is  overwritten  by
77               H*C or H'*C or C*H or C*H'.
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79       LDC     (input) INTEGER
80               The leading dimension of the array C. LDC >= max(1,M).
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82       WORK    (workspace) COMPLEX array, dimension (LDWORK,K)
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84       LDWORK  (input) INTEGER
85               The leading dimension of the array WORK.  If SIDE = 'L', LDWORK
86               >= max(1,N); if SIDE = 'R', LDWORK >= max(1,M).
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FURTHER DETAILS

89       Based on contributions by
90         A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA
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94 LAPACK routine (version 3.2)    November 2008                       CLARZB(1)
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