Contents
zunmqr - overwrite the general complex M-by-N matrix C with
SIDE = 'L' SIDE = 'R' TRANS = 'N'
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, doublecomplex *a, long lda, doublecomplex *tau,
doublecomplex *c, long ldc, long *info);
zunmqr 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 CGEQRF. 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.
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 CGEQRF 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 ele-
mentary reflector H(i), as returned by CGEQRF.
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