Contents
zunmtr - overwrite the general complex M-by-N matrix C with
SIDE = 'L' SIDE = 'R' TRANS = 'N'
SUBROUTINE ZUNMTR(SIDE, UPLO, TRANS, M, N, A, LDA, TAU, C, LDC, WORK,
LWORK, INFO)
CHARACTER * 1 SIDE, UPLO, TRANS
DOUBLE COMPLEX A(LDA,*), TAU(*), C(LDC,*), WORK(*)
INTEGER M, N, LDA, LDC, LWORK, INFO
SUBROUTINE ZUNMTR_64(SIDE, UPLO, TRANS, M, N, A, LDA, TAU, C, LDC,
WORK, LWORK, INFO)
CHARACTER * 1 SIDE, UPLO, TRANS
DOUBLE COMPLEX A(LDA,*), TAU(*), C(LDC,*), WORK(*)
INTEGER*8 M, N, LDA, LDC, LWORK, INFO
F95 INTERFACE
SUBROUTINE UNMTR(SIDE, UPLO, [TRANS], [M], [N], A, [LDA], TAU, C,
[LDC], [WORK], [LWORK], [INFO])
CHARACTER(LEN=1) :: SIDE, UPLO, TRANS
COMPLEX(8), DIMENSION(:) :: TAU, WORK
COMPLEX(8), DIMENSION(:,:) :: A, C
INTEGER :: M, N, LDA, LDC, LWORK, INFO
SUBROUTINE UNMTR_64(SIDE, UPLO, [TRANS], [M], [N], A, [LDA], TAU, C,
[LDC], [WORK], [LWORK], [INFO])
CHARACTER(LEN=1) :: SIDE, UPLO, TRANS
COMPLEX(8), DIMENSION(:) :: TAU, WORK
COMPLEX(8), DIMENSION(:,:) :: A, C
INTEGER(8) :: M, N, LDA, LDC, LWORK, INFO
C INTERFACE
#include <sunperf.h>
void zunmtr(char side, char uplo, char trans, int m, int n,
doublecomplex *a, int lda, doublecomplex *tau,
doublecomplex *c, int ldc, int *info);
void zunmtr_64(char side, char uplo, char trans, long m,
long n, doublecomplex *a, long lda, doublecomplex
*tau, doublecomplex *c, long ldc, long *info);
zunmtr 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 of order nq, with nq = m
if SIDE = 'L' and nq = n if SIDE = 'R'. Q is defined as the
product of nq-1 elementary reflectors, as returned by
CHETRD:
if UPLO = 'U', Q = H(nq-1) . . . H(2) H(1);
if UPLO = 'L', Q = H(1) H(2) . . . H(nq-1).
SIDE (input)
= 'L': apply Q or Q**H from the Left;
= 'R': apply Q or Q**H from the Right.
UPLO (input)
= 'U': Upper triangle of A contains elementary
reflectors from CHETRD; = 'L': Lower triangle of A
contains elementary reflectors from CHETRD.
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.
A (input) (LDA,M) if SIDE = 'L' (LDA,N) if SIDE = 'R' The
vectors which define the elementary reflectors, as
returned by CHETRD.
LDA (input)
The leading dimension of the array A. LDA >=
max(1,M) if SIDE = 'L'; LDA >= max(1,N) if SIDE =
'R'.
TAU (input)
(M-1) if SIDE = 'L' (N-1) if SIDE = 'R' TAU(i)
must contain the scalar factor of the elementary
reflector H(i), as returned by CHETRD.
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