dlarzb
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
SUBROUTINE DLARZB( SIDE, TRANS, DIRECT, STOREV, M, N, K, L, V, LDV,
* T, LDT, C, LDC, WORK, LDWORK)
CHARACTER * 1 SIDE, TRANS, DIRECT, STOREV
INTEGER M, N, K, L, LDV, LDT, LDC, LDWORK
DOUBLE PRECISION V(LDV,*), T(LDT,*), C(LDC,*), WORK(LDWORK,*)
SUBROUTINE DLARZB_64( SIDE, TRANS, DIRECT, STOREV, M, N, K, L, V,
* LDV, T, LDT, C, LDC, WORK, LDWORK)
CHARACTER * 1 SIDE, TRANS, DIRECT, STOREV
INTEGER*8 M, N, K, L, LDV, LDT, LDC, LDWORK
DOUBLE PRECISION V(LDV,*), T(LDT,*), C(LDC,*), WORK(LDWORK,*)
SUBROUTINE LARZB( SIDE, TRANS, DIRECT, STOREV, [M], [N], K, L, V,
* [LDV], T, [LDT], C, [LDC], [WORK], [LDWORK])
CHARACTER(LEN=1) :: SIDE, TRANS, DIRECT, STOREV
INTEGER :: M, N, K, L, LDV, LDT, LDC, LDWORK
REAL(8), DIMENSION(:,:) :: V, T, C, WORK
SUBROUTINE LARZB_64( SIDE, TRANS, DIRECT, STOREV, [M], [N], K, L, V,
* [LDV], T, [LDT], C, [LDC], [WORK], [LDWORK])
CHARACTER(LEN=1) :: SIDE, TRANS, DIRECT, STOREV
INTEGER(8) :: M, N, K, L, LDV, LDT, LDC, LDWORK
REAL(8), DIMENSION(:,:) :: V, T, C, WORK
#include <sunperf.h>
void dlarzb(char side, char trans, char direct, char storev, int m, int n, int k, int l, double *v, int ldv, double *t, int ldt, double *c, int ldc, int ldwork);
void dlarzb_64(char side, char trans, char direct, char storev, long m, long n, long k, long l, double *v, long ldv, double *t, long ldt, double *c, long ldc, long ldwork);
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.
-
* SIDE (input)
-
-
* TRANS (input)
-
-
* DIRECT (input)
-
Indicates how H is formed from a product of elementary
reflectors
-
* STOREV (input)
-
Indicates how the vectors which define the elementary
reflectors are stored:
-
* M (input)
-
The number of rows of the matrix C.
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* N (input)
-
The number of columns of the matrix C.
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* K (input)
-
The order of the matrix T (= the number of elementary
reflectors whose product defines the block reflector).
-
* L (input)
-
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)
-
If STOREV = 'C', NV = K; if STOREV = 'R', NV = L.
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* LDV (input)
-
The leading dimension of the array V.
If STOREV = 'C', LDV >= L; if STOREV = 'R', LDV >= K.
-
* T (input)
-
The triangular K-by-K matrix T in the representation of the
block reflector.
-
* LDT (input)
-
The leading dimension of the array T. LDT >= K.
-
* C (input/output)
-
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)
-
The leading dimension of the array C. LDC >= max(1,M).
-
* WORK (workspace)
-
dimension(MAX(M,N),K)
-
* LDWORK (input)
-
The leading dimension of the array WORK.
If SIDE = 'L', LDWORK >= max(1,N);
if SIDE = 'R', LDWORK >= max(1,M).
.SH FURTHER DETAILS
Based on contributions by
A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA