dopgtr (3p)

Name

dopgtr - 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 DSPTRD using packed storage

Synopsis

SUBROUTINE DOPGTR(UPLO, N, AP, TAU, Q, LDQ, WORK, INFO)

CHARACTER*1 UPLO
INTEGER N, LDQ, INFO
DOUBLE PRECISION AP(*), TAU(*), Q(LDQ,*), WORK(*)

SUBROUTINE DOPGTR_64(UPLO, N, AP, TAU, Q, LDQ, WORK, INFO)

CHARACTER*1 UPLO
INTEGER*8 N, LDQ, INFO
DOUBLE PRECISION 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(8), DIMENSION(:) :: AP, TAU, WORK
REAL(8), DIMENSION(:,:) :: Q

SUBROUTINE OPGTR_64(UPLO, N, AP, TAU, Q, LDQ, WORK, INFO)

CHARACTER(LEN=1) :: UPLO
INTEGER(8) :: N, LDQ, INFO
REAL(8), DIMENSION(:) :: AP, TAU, WORK
REAL(8), DIMENSION(:,:) :: Q




C INTERFACE
#include <sunperf.h>

void  dopgtr(char  uplo, int n, double *ap, double *tau, double *q, int
ldq, int *info);

void dopgtr_64(char uplo, long n, double *ap, double *tau,  double  *q,
long ldq, long *info);

Description

Oracle Solaris Studio Performance Library                           dopgtr(3P)



NAME
       dopgtr  -  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
       DSPTRD using packed storage


SYNOPSIS
       SUBROUTINE DOPGTR(UPLO, N, AP, TAU, Q, LDQ, WORK, INFO)

       CHARACTER*1 UPLO
       INTEGER N, LDQ, INFO
       DOUBLE PRECISION AP(*), TAU(*), Q(LDQ,*), WORK(*)

       SUBROUTINE DOPGTR_64(UPLO, N, AP, TAU, Q, LDQ, WORK, INFO)

       CHARACTER*1 UPLO
       INTEGER*8 N, LDQ, INFO
       DOUBLE PRECISION 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(8), DIMENSION(:) :: AP, TAU, WORK
       REAL(8), DIMENSION(:,:) :: Q

       SUBROUTINE OPGTR_64(UPLO, N, AP, TAU, Q, LDQ, WORK, INFO)

       CHARACTER(LEN=1) :: UPLO
       INTEGER(8) :: N, LDQ, INFO
       REAL(8), DIMENSION(:) :: AP, TAU, WORK
       REAL(8), DIMENSION(:,:) :: Q




   C INTERFACE
       #include <sunperf.h>

       void  dopgtr(char  uplo, int n, double *ap, double *tau, double *q, int
                 ldq, int *info);

       void dopgtr_64(char uplo, long n, double *ap, double *tau,  double  *q,
                 long ldq, long *info);



PURPOSE
       dopgtr  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
       DSPTRD 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 DSPTRD; = 'L': Lower triangular  packed  storage  used  in
                 previous call to DSPTRD.


       N (input) The order of the matrix Q. N >= 0.


       AP (input)
                 The  vectors  which  define  the  elementary  reflectors,  as
                 returned by DSPTRD.


       TAU (input)
                 TAU(i) must contain  the  scalar  factor  of  the  elementary
                 reflector H(i), as returned by DSPTRD.


       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




                                  7 Nov 2015                        dopgtr(3P)