sopgtr(3P) Sun Performance Library sopgtr(3P)NAMEsopgtr - generate a real orthogonal matrix Q which is defined as the
product of n-1 elementary reflectors H(i) of order n, as returned by
SSPTRD using packed storage
SYNOPSIS
SUBROUTINE SOPGTR(UPLO, N, AP, TAU, Q, LDQ, WORK, INFO)
CHARACTER * 1 UPLO
INTEGER N, LDQ, INFO
REAL AP(*), TAU(*), Q(LDQ,*), WORK(*)
SUBROUTINE SOPGTR_64(UPLO, N, AP, TAU, Q, LDQ, WORK, INFO)
CHARACTER * 1 UPLO
INTEGER*8 N, LDQ, INFO
REAL AP(*), TAU(*), Q(LDQ,*), WORK(*)
F95 INTERFACE
SUBROUTINE OPGTR(UPLO, [N], AP, TAU, Q, [LDQ], [WORK], [INFO])
CHARACTER(LEN=1) :: UPLO
INTEGER :: N, LDQ, INFO
REAL, DIMENSION(:) :: AP, TAU, WORK
REAL, DIMENSION(:,:) :: Q
SUBROUTINE OPGTR_64(UPLO, [N], AP, TAU, Q, [LDQ], [WORK], [INFO])
CHARACTER(LEN=1) :: UPLO
INTEGER(8) :: N, LDQ, INFO
REAL, DIMENSION(:) :: AP, TAU, WORK
REAL, DIMENSION(:,:) :: Q
C INTERFACE
#include <sunperf.h>
void sopgtr(char uplo, int n, float *ap, float *tau, float *q, int ldq,
int *info);
void sopgtr_64(char uplo, long n, float *ap, float *tau, float *q, long
ldq, long *info);
PURPOSEsopgtr generates a real orthogonal matrix Q which is defined as the
product of n-1 elementary reflectors H(i) of order n, as returned by
SSPTRD using packed storage:
if UPLO = 'U', Q = H(n-1) . . . H(2)H(1),
if UPLO = 'L', Q = H(1)H(2) . . . H(n-1).
ARGUMENTS
UPLO (input)
= 'U': Upper triangular packed storage used in previous call
to SSPTRD; = 'L': Lower triangular packed storage used in
previous call to SSPTRD.
N (input) The order of the matrix Q. N >= 0.
AP (input)
The vectors which define the elementary reflectors, as
returned by SSPTRD.
TAU (input)
TAU(i) must contain the scalar factor of the elementary
reflector H(i), as returned by SSPTRD.
Q (output)
The N-by-N orthogonal matrix Q.
LDQ (input)
The leading dimension of the array Q. LDQ >= max(1,N).
WORK (workspace)
dimension(N-1)
INFO (output)
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
6 Mar 2009 sopgtr(3P)
