dgemqrt - N matrix C with Q*C, C*Q, Q**T*C, or C*Q**T depending on values of SIDE and TRANS
SUBROUTINE DGEMQRT(SIDE, TRANS, M, N, K, NB, V, LDV, T, LDT, C, LDC, WORK, INFO) CHARACTER*1 SIDE, TRANS INTEGER INFO, K, LDV, LDC, M, N, NB, LDT DOUBLE PRECISION V(LDV,*), C(LDC,*), T(LDT,*), WORK(*) SUBROUTINE DGEMQRT_64(SIDE, TRANS, M, N, K, NB, V, LDV, T, LDT, C, LDC, WORK, INFO) CHARACTER*1 SIDE, TRANS INTEGER*8 INFO, K, LDV, LDC, M, N, NB, LDT DOUBLE PRECISION V(LDV,*), C(LDC,*), T(LDT,*), WORK(*) F95 INTERFACE SUBROUTINE GEMQRT(SIDE, TRANS, M, N, K, NB, V, LDV, T, LDT, C, LDC, WORK, INFO) INTEGER :: M, N, K, NB, LDV, LDT, LDC, INFO CHARACTER(LEN=1) :: SIDE, TRANS REAL(8), DIMENSION(:,:) :: V, T, C REAL(8), DIMENSION(:) :: WORK SUBROUTINE GEMQRT_64(SIDE, TRANS, M, N, K, NB, V, LDV, T, LDT, C, LDC, WORK, INFO) INTEGER(8) :: M, N, K, NB, LDV, LDT, LDC, INFO CHARACTER(LEN=1) :: SIDE, TRANS REAL(8), DIMENSION(:,:) :: V, T, C REAL(8), DIMENSION(:) :: WORK C INTERFACE #include <sunperf.h> void dgemqrt (char side, char trans, int m, int n, int k, int nb, dou- ble *v, int ldv, double *t, int ldt, double *c, int ldc, int *info); void dgemqrt_64 (char side, char trans, long m, long n, long k, long nb, double *v, long ldv, double *t, long ldt, double *c, long ldc, long *info);
Oracle Solaris Studio Performance Library dgemqrt(3P)
NAME
dgemqrt - overwrite the general real M-by-N matrix C with Q*C, C*Q,
Q**T*C, or C*Q**T depending on values of SIDE and TRANS
SYNOPSIS
SUBROUTINE DGEMQRT(SIDE, TRANS, M, N, K, NB, V, LDV, T, LDT, C, LDC,
WORK, INFO)
CHARACTER*1 SIDE, TRANS
INTEGER INFO, K, LDV, LDC, M, N, NB, LDT
DOUBLE PRECISION V(LDV,*), C(LDC,*), T(LDT,*), WORK(*)
SUBROUTINE DGEMQRT_64(SIDE, TRANS, M, N, K, NB, V, LDV, T, LDT, C, LDC,
WORK, INFO)
CHARACTER*1 SIDE, TRANS
INTEGER*8 INFO, K, LDV, LDC, M, N, NB, LDT
DOUBLE PRECISION V(LDV,*), C(LDC,*), T(LDT,*), WORK(*)
F95 INTERFACE
SUBROUTINE GEMQRT(SIDE, TRANS, M, N, K, NB, V, LDV, T, LDT, C, LDC,
WORK, INFO)
INTEGER :: M, N, K, NB, LDV, LDT, LDC, INFO
CHARACTER(LEN=1) :: SIDE, TRANS
REAL(8), DIMENSION(:,:) :: V, T, C
REAL(8), DIMENSION(:) :: WORK
SUBROUTINE GEMQRT_64(SIDE, TRANS, M, N, K, NB, V, LDV, T, LDT, C, LDC,
WORK, INFO)
INTEGER(8) :: M, N, K, NB, LDV, LDT, LDC, INFO
CHARACTER(LEN=1) :: SIDE, TRANS
REAL(8), DIMENSION(:,:) :: V, T, C
REAL(8), DIMENSION(:) :: WORK
C INTERFACE
#include <sunperf.h>
void dgemqrt (char side, char trans, int m, int n, int k, int nb, dou-
ble *v, int ldv, double *t, int ldt, double *c, int ldc, int
*info);
void dgemqrt_64 (char side, char trans, long m, long n, long k, long
nb, double *v, long ldv, double *t, long ldt, double *c, long
ldc, long *info);
PURPOSE
dgemqrt overwrites the general real M-by-N matrix C with
SIDE = 'L' SIDE = 'R'
TRANS = 'N': Q*C C*Q
TRANS = 'T': Q**T*C C*Q**T
where Q is a real orthogonal matrix defined as the product of K elemen-
tary reflectors:
Q = H(1)*H(2) . . . H(K) = I - V*T*V**T
generated using the compact WY representation as returned by DGEQRT. Q
is of order M if SIDE = 'L' and of order N if SIDE = 'R'.
ARGUMENTS
SIDE (input)
SIDE is CHARACTER*1
= 'L': apply Q or Q**T from the Left;
= 'R': apply Q or Q**T from the Right.
TRANS (input)
TRANS is CHARACTER*1
= 'N': No transpose, apply Q;
= 'C': Transpose, apply Q**T.
M (input)
M is INTEGER
The number of rows of the matrix C. M >= 0.
N (input)
N is INTEGER
The number of columns of the matrix C. N >= 0.
K (input)
K is INTEGER
The number of elementary reflectors whose product defines the
matrix Q.
If SIDE = 'L', M >= K >= 0;
if SIDE = 'R', N >= K >= 0.
NB (input)
NB is INTEGER
The block size used for the storage of T.
K >= NB >= 1.
This must be the same value of NB used to generate T in CGE-
QRT.
V (input)
V is DOUBLE PRECISION array, dimension (LDV,K)
The i-th column must contain the vector which defines the
elementary reflector H(i), for i = 1,2,...,K, as returned by
CGEQRT in the first K columns of its array argument A.
LDV (input)
LDV is INTEGER
The leading dimension of the array V.
If SIDE = 'L', LDA >= max(1,M);
if SIDE = 'R', LDA >= max(1,N).
T (input)
T is DOUBLE PRECISION array, dimension (LDT,K)
The upper triangular factors of the block reflectors as
returned by CGEQRT, stored as a NB-by-N matrix.
LDT (input)
LDT is INTEGER
The leading dimension of the array T. LDT >= NB.
C (input/output)
C is DOUBLE PRECISION array, dimension (LDC,N)
On entry, the M-by-N matrix C.
On exit, C is overwritten by Q*C, Q**T*C, C*Q**T or C*Q.
LDC (input)
LDC is INTEGER
The leading dimension of the array C.
LDC >= max(1,M).
WORK (output)
WORK is DOUBLE PRECISION array. The dimension of WORK is N*NB
if SIDE = 'L', or M*NB if SIDE = 'R'.
INFO (output)
INFO is INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
7 Nov 2015 dgemqrt(3P)