Contents
cunmbr - VECT = 'Q', CUNMBR overwrites the general complex
M-by-N matrix C with SIDE = 'L' SIDE = 'R' TRANS = 'N'
SUBROUTINE CUNMBR(VECT, SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC,
WORK, LWORK, INFO)
CHARACTER * 1 VECT, SIDE, TRANS
COMPLEX A(LDA,*), TAU(*), C(LDC,*), WORK(*)
INTEGER M, N, K, LDA, LDC, LWORK, INFO
SUBROUTINE CUNMBR_64(VECT, SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC,
WORK, LWORK, INFO)
CHARACTER * 1 VECT, SIDE, TRANS
COMPLEX A(LDA,*), TAU(*), C(LDC,*), WORK(*)
INTEGER*8 M, N, K, LDA, LDC, LWORK, INFO
F95 INTERFACE
SUBROUTINE UNMBR(VECT, SIDE, [TRANS], [M], [N], K, A, [LDA], TAU, C,
[LDC], [WORK], [LWORK], [INFO])
CHARACTER(LEN=1) :: VECT, SIDE, TRANS
COMPLEX, DIMENSION(:) :: TAU, WORK
COMPLEX, DIMENSION(:,:) :: A, C
INTEGER :: M, N, K, LDA, LDC, LWORK, INFO
SUBROUTINE UNMBR_64(VECT, SIDE, [TRANS], [M], [N], K, A, [LDA], TAU,
C, [LDC], [WORK], [LWORK], [INFO])
CHARACTER(LEN=1) :: VECT, SIDE, TRANS
COMPLEX, DIMENSION(:) :: TAU, WORK
COMPLEX, DIMENSION(:,:) :: A, C
INTEGER(8) :: M, N, K, LDA, LDC, LWORK, INFO
C INTERFACE
#include <sunperf.h>
void cunmbr(char vect, char side, char trans, int m, int n,
int k, complex *a, int lda, complex *tau, complex
*c, int ldc, int *info);
void cunmbr_64(char vect, char side, char trans, long m,
long n, long k, complex *a, long lda, complex
*tau, complex *c, long ldc, long *info);
cunmbr VECT = 'Q', CUNMBR overwrites the general complex M-
by-N matrix C with
SIDE = 'L' SIDE = 'R' TRANS = 'N':
Q * C C * Q TRANS = 'C': Q**H * C C *
Q**H
If VECT = 'P', CUNMBR overwrites the general complex M-by-N
matrix C with
SIDE = 'L' SIDE = 'R'
TRANS = 'N': P * C C * P
TRANS = 'C': P**H * C C * P**H
Here Q and P**H are the unitary matrices determined by
CGEBRD when reducing a complex matrix A to bidiagonal form:
A = Q * B * P**H. Q and P**H are defined as products of ele-
mentary reflectors H(i) and G(i) respectively.
Let nq = m if SIDE = 'L' and nq = n if SIDE = 'R'. Thus nq
is the order of the unitary matrix Q or P**H that is
applied.
If VECT = 'Q', A is assumed to have been an NQ-by-K matrix:
if nq >= k, Q = H(1) H(2) . . . H(k);
if nq < k, Q = H(1) H(2) . . . H(nq-1).
If VECT = 'P', A is assumed to have been a K-by-NQ matrix:
if k < nq, P = G(1) G(2) . . . G(k);
if k >= nq, P = G(1) G(2) . . . G(nq-1).
VECT (input)
= 'Q': apply Q or Q**H;
= 'P': apply P or P**H.
SIDE (input)
= 'L': apply Q, Q**H, P or P**H from the Left;
= 'R': apply Q, Q**H, P or P**H from the Right.
TRANS (input)
= 'N': No transpose, apply Q or P;
= 'C': Conjugate transpose, apply Q**H or P**H.
TRANS is defaulted to 'N' for F95 INTERFACE.
M (input) The number of rows of the matrix C. M >= 0.
N (input) The number of columns of the matrix C. N >= 0.
K (input) If VECT = 'Q', the number of columns in the origi-
nal matrix reduced by CGEBRD. If VECT = 'P', the
number of rows in the original matrix reduced by
CGEBRD. K >= 0.
A (input) (LDA,min(nq,K)) if VECT = 'Q' (LDA,nq) if
VECT = 'P' The vectors which define the elementary
reflectors H(i) and G(i), whose products determine
the matrices Q and P, as returned by CGEBRD.
LDA (input)
The leading dimension of the array A. If VECT =
'Q', LDA >= max(1,nq); if VECT = 'P', LDA >=
max(1,min(nq,K)).
TAU (input)
TAU(i) must contain the scalar factor of the ele-
mentary reflector H(i) or G(i) which determines Q
or P, as returned by CGEBRD in the array argument
TAUQ or TAUP.
C (input/output)
On entry, the M-by-N matrix C. On exit, C is
overwritten by Q*C or Q**H*C or C*Q**H or C*Q or
P*C or P**H*C or C*P or C*P**H.
LDC (input)
The leading dimension of the array C. LDC >=
max(1,M).
WORK (workspace)
On exit, if INFO = 0, WORK(1) returns the optimal
LWORK.
LWORK (input)
The dimension of the array WORK. If SIDE = 'L',
LWORK >= max(1,N); if SIDE = 'R', LWORK >=
max(1,M). For optimum performance LWORK >= N*NB
if SIDE = 'L', and LWORK >= M*NB if SIDE = 'R',
where NB is the optimal blocksize.
If LWORK = -1, then a workspace query is assumed;
the routine only calculates the optimal size of
the WORK array, returns this value as the first
entry of the WORK array, and no error message
related to LWORK is issued by XERBLA.
INFO (output)
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an ille-
gal value