zunmqr(3P) Sun Performance Library zunmqr(3P)NAMEzunmqr - overwrite the general complex M-by-N matrix C with SIDE =
'L' SIDE = 'R' TRANS = 'N'
SYNOPSIS
SUBROUTINE ZUNMQR(SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, WORK,
LWORK, INFO)
CHARACTER * 1 SIDE, TRANS
DOUBLE COMPLEX A(LDA,*), TAU(*), C(LDC,*), WORK(*)
INTEGER M, N, K, LDA, LDC, LWORK, INFO
SUBROUTINE ZUNMQR_64(SIDE, TRANS, M, N, K, 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, LDA, LDC, LWORK, INFO
F95 INTERFACE
SUBROUTINE UNMQR(SIDE, [TRANS], [M], [N], [K], 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, LDA, LDC, LWORK, INFO
SUBROUTINE UNMQR_64(SIDE, [TRANS], [M], [N], [K], 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, LDA, LDC, LWORK, INFO
C INTERFACE
#include <sunperf.h>
void zunmqr(char side, char trans, int m, int n, int k, doublecomplex
*a, int lda, doublecomplex *tau, doublecomplex *c, int ldc,
int *info);
void zunmqr_64(char side, char trans, long m, long n, long k, double‐
complex *a, long lda, doublecomplex *tau, doublecomplex *c,
long ldc, long *info);
PURPOSEzunmqr 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 elemen‐
tary reflectors
Q = H(1)H(2) . . . H(k)
as returned by ZGEQRF. Q is of order M if SIDE = 'L' and of order N if
SIDE = 'R'.
ARGUMENTS
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.
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) The number of elementary reflectors whose product defines the
matrix Q. If SIDE = 'L', M >= K >= 0; if SIDE = 'R', N >= K
>= 0.
A (input) The i-th column must contain the vector which defines the
elementary reflector H(i), for i = 1,2,...,k, as returned by
ZGEQRF in the first k columns of its array argument A. A is
modified by the routine but restored on exit.
LDA (input)
The leading dimension of the array A. If SIDE = 'L', LDA >=
max(1,M); if SIDE = 'R', LDA >= max(1,N).
TAU (input)
TAU(i) must contain the scalar factor of the elementary
reflector H(i), as returned by ZGEQRF.
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 per‐
formance 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 illegal value
6 Mar 2009 zunmqr(3P)
