Contents
zunmrz - overwrite the general complex M-by-N matrix C with
SIDE = 'L' SIDE = 'R' TRANS = 'N'
SUBROUTINE ZUNMRZ(SIDE, TRANS, M, N, K, L, A, LDA, TAU, C, LDC, WORK,
LWORK, INFO)
CHARACTER * 1 SIDE, TRANS
DOUBLE COMPLEX A(LDA,*), TAU(*), C(LDC,*), WORK(*)
INTEGER M, N, K, L, LDA, LDC, LWORK, INFO
SUBROUTINE ZUNMRZ_64(SIDE, TRANS, M, N, K, L, A, LDA, TAU, C, LDC,
WORK, LWORK, INFO)
CHARACTER * 1 SIDE, TRANS
DOUBLE COMPLEX A(LDA,*), TAU(*), C(LDC,*), WORK(*)
INTEGER*8 M, N, K, L, LDA, LDC, LWORK, INFO
F95 INTERFACE
SUBROUTINE ZUNMRZ(SIDE, TRANS, M, N, K, L, A, LDA, TAU, C, LDC,
WORK, LWORK, INFO)
CHARACTER(LEN=1) :: SIDE, TRANS
COMPLEX(8), DIMENSION(:) :: TAU, WORK
COMPLEX(8), DIMENSION(:,:) :: A, C
INTEGER :: M, N, K, L, LDA, LDC, LWORK, INFO
SUBROUTINE ZUNMRZ_64(SIDE, TRANS, M, N, K, L, A, LDA, TAU, C, LDC,
WORK, LWORK, INFO)
CHARACTER(LEN=1) :: SIDE, TRANS
COMPLEX(8), DIMENSION(:) :: TAU, WORK
COMPLEX(8), DIMENSION(:,:) :: A, C
INTEGER(8) :: M, N, K, L, LDA, LDC, LWORK, INFO
C INTERFACE
#include <sunperf.h>
void zunmrz(char side, char trans, int m, int n, int k, int
l, doublecomplex *a, int lda, doublecomplex *tau,
doublecomplex *c, int ldc, int *info);
void zunmrz_64(char side, char trans, long m, long n, long
k, long l, doublecomplex *a, long lda, doublecom-
plex *tau, doublecomplex *c, long ldc, long
*info);
zunmrz overwrites the general complex M-by-N matrix C with
TRANS = 'C': Q**H * C C * Q**H
where Q is a complex unitary matrix defined as the product
of k elementary reflectors
Q = H(1) H(2) . . . H(k)
as returned by CTZRZF. Q is of order M if SIDE = 'L' and of
order N if SIDE = 'R'.
SIDE (input)
= 'L': apply Q or Q**H from the Left;
= 'R': apply Q or Q**H from the Right.
TRANS (input)
= 'N': No transpose, apply Q;
= 'C': Conjugate transpose, apply Q**H.
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) The number of elementary reflectors whose product
defines the matrix Q. If SIDE = 'L', M >= K >= 0;
if SIDE = 'R', N >= K >= 0.
L (input) The number of columns of the matrix A containing
the meaningful part of the Householder reflectors.
If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L
>= 0.
A (input) (LDA,M) if SIDE = 'L', (LDA,N) if SIDE = 'R' The
i-th row must contain the vector which defines the
elementary reflector H(i), for i = 1,2,...,k, as
returned by CTZRZF in the last k rows of its array
argument A. A is modified by the routine but
restored on exit.
LDA (input)
The leading dimension of the array A. LDA >=
max(1,K).
TAU (input)
TAU(i) must contain the scalar factor of the ele-
mentary reflector H(i), as returned by CTZRZF.
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.
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
Based on contributions by
A. Petitet, Computer Science Dept., Univ. of Tenn., Knox-
ville, USA