zunmhr(3P) Sun Performance Library zunmhr(3P)NAMEzunmhr - overwrite the general complex M-by-N matrix C with Q*C or
Q**H*C or C*Q**H or C*Q.
SYNOPSIS
SUBROUTINE ZUNMHR(SIDE, TRANS, M, N, ILO, IHI, A, LDA, TAU, C, LDC,
WORK, LWORK, INFO)
CHARACTER * 1 SIDE, TRANS
DOUBLE COMPLEX A(LDA,*), TAU(*), C(LDC,*), WORK(*)
INTEGER M, N, ILO, IHI, LDA, LDC, LWORK, INFO
SUBROUTINE ZUNMHR_64(SIDE, TRANS, M, N, ILO, IHI, A, LDA, TAU, C,
LDC, WORK, LWORK, INFO)
CHARACTER * 1 SIDE, TRANS
DOUBLE COMPLEX A(LDA,*), TAU(*), C(LDC,*), WORK(*)
INTEGER*8 M, N, ILO, IHI, LDA, LDC, LWORK, INFO
F95 INTERFACE
SUBROUTINE UNMHR(SIDE, [TRANS], [M], [N], ILO, IHI, 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, ILO, IHI, LDA, LDC, LWORK, INFO
SUBROUTINE UNMHR_64(SIDE, [TRANS], [M], [N], ILO, IHI, 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, ILO, IHI, LDA, LDC, LWORK, INFO
C INTERFACE
#include <sunperf.h>
void zunmhr(char side, char trans, int m, int n, int ilo, int ihi, dou‐
blecomplex *a, int lda, doublecomplex *tau, doublecomplex *c,
int ldc, int *info);
void zunmhr_64(char side, char trans, long m, long n, long ilo, long
ihi, doublecomplex *a, long lda, doublecomplex *tau, double‐
complex *c, long ldc, long *info);
PURPOSEzunmhr 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
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 IHI-ILO
elementary reflectors, as returned by ZGEHRD:
Q = H(ilo) H(ilo+1) . . . H(ihi-1).
ARGUMENTS
SIDE (input)
= 'L': apply Q or Q**H from the Left;
= 'R': apply Q or Q**H from the Right.
TRANS (input)
= 'N': apply Q (No transpose)
= 'C': apply Q**H (Conjugate transpose)
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.
ILO (input)
ILO and IHI must have the same values as in the previous call
of ZGEHRD. Q is equal to the unit matrix except in the subma‐
trix Q(ilo+1:ihi,ilo+1:ihi). If SIDE = 'L', then 1 <= ILO <=
IHI <= M, if M > 0, and ILO = 1 and IHI = 0, if M = 0; if
SIDE = 'R', then 1 <= ILO <= IHI <= N, if N > 0, and ILO = 1
and IHI = 0, if N = 0.
IHI (input)
See the description of ILO.
A (input) (LDA,M) if SIDE = 'L' (LDA,N) if SIDE = 'R' The vectors which
define the elementary reflectors, as returned by ZGEHRD.
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 ZGEHRD.
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 zunmhr(3P)
