ZLARZB
Purpose
ZLARZB applies a complex block reflector H or its transpose H**H
to a complex distributed M-by-N C from the left or the right.
Currently, only STOREV = 'R' and DIRECT = 'B' are supported.
to a complex 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**H from the Left
= 'R': apply H or H**H from the Right |
TRANS |
(input) CHARACTER*1
= 'N': apply H (No transpose)
= 'C': apply H**H (Conjugate 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) COMPLEX*16 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) COMPLEX*16 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) COMPLEX*16 array, dimension (LDC,N)
On entry, the M-by-N matrix C.
On exit, C is overwritten by H*C or H**H*C or C*H or C*H**H. |
LDC |
(input) INTEGER
The leading dimension of the array C. LDC >= max(1,M).
|
WORK |
(workspace) COMPLEX*16 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
A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA