dorgqr (3p)

Name

dorgqr - N real matrix Q with orthonormal columns,

Synopsis

SUBROUTINE DORGQR(M, N, K, A, LDA, TAU, WORK, LDWORK, INFO)

INTEGER M, N, K, LDA, LDWORK, INFO
DOUBLE PRECISION A(LDA,*), TAU(*), WORK(*)

SUBROUTINE DORGQR_64(M, N, K, A, LDA, TAU, WORK, LDWORK, INFO)

INTEGER*8 M, N, K, LDA, LDWORK, INFO
DOUBLE PRECISION A(LDA,*), TAU(*), WORK(*)




F95 INTERFACE
SUBROUTINE ORGQR(M, N, K, A, LDA, TAU, WORK, LDWORK, INFO)

INTEGER :: M, N, K, LDA, LDWORK, INFO
REAL(8), DIMENSION(:) :: TAU, WORK
REAL(8), DIMENSION(:,:) :: A

SUBROUTINE ORGQR_64(M, N, K, A, LDA, TAU, WORK, LDWORK,
INFO)

INTEGER(8) :: M, N, K, LDA, LDWORK, INFO
REAL(8), DIMENSION(:) :: TAU, WORK
REAL(8), DIMENSION(:,:) :: A




C INTERFACE
#include <sunperf.h>

void  dorgqr(int  m, int n, int k, double *a, int lda, double *tau, int
*info);

void dorgqr_64(long m, long n, long k,  double  *a,  long  lda,  double
*tau, long *info);

Description

Oracle Solaris Studio Performance Library                           dorgqr(3P)



NAME
       dorgqr - generate an M-by-N real matrix Q with orthonormal columns,


SYNOPSIS
       SUBROUTINE DORGQR(M, N, K, A, LDA, TAU, WORK, LDWORK, INFO)

       INTEGER M, N, K, LDA, LDWORK, INFO
       DOUBLE PRECISION A(LDA,*), TAU(*), WORK(*)

       SUBROUTINE DORGQR_64(M, N, K, A, LDA, TAU, WORK, LDWORK, INFO)

       INTEGER*8 M, N, K, LDA, LDWORK, INFO
       DOUBLE PRECISION A(LDA,*), TAU(*), WORK(*)




   F95 INTERFACE
       SUBROUTINE ORGQR(M, N, K, A, LDA, TAU, WORK, LDWORK, INFO)

       INTEGER :: M, N, K, LDA, LDWORK, INFO
       REAL(8), DIMENSION(:) :: TAU, WORK
       REAL(8), DIMENSION(:,:) :: A

       SUBROUTINE ORGQR_64(M, N, K, A, LDA, TAU, WORK, LDWORK,
              INFO)

       INTEGER(8) :: M, N, K, LDA, LDWORK, INFO
       REAL(8), DIMENSION(:) :: TAU, WORK
       REAL(8), DIMENSION(:,:) :: A




   C INTERFACE
       #include <sunperf.h>

       void  dorgqr(int  m, int n, int k, double *a, int lda, double *tau, int
                 *info);

       void dorgqr_64(long m, long n, long k,  double  *a,  long  lda,  double
                 *tau, long *info);



PURPOSE
       dorgqr  generates  an  M-by-N  real  matrix Q with orthonormal columns,
       which is defined as the first N columns of a product  of  K  elementary
       reflectors of order M

             Q  =  H(1) H(2) . . . H(k)

       as returned by DGEQRF.


ARGUMENTS
       M (input) The number of rows of the matrix Q. M >= 0.


       N (input) The number of columns of the matrix Q. M >= N >= 0.


       K (input) The number of elementary reflectors whose product defines the
                 matrix Q. N >= K >= 0.


       A (input/output)
                 On entry, the i-th  column  must  contain  the  vector  which
                 defines  the elementary reflector H(i), for i = 1,2,...,k, as
                 returned by DGEQRF in the first k columns of its array  argu-
                 ment A.  On exit, the M-by-N matrix Q.


       LDA (input)
                 The first dimension of the array A. LDA >= max(1,M).


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


       WORK (workspace)
                 On exit, if INFO = 0, WORK(1) returns the optimal LDWORK.


       LDWORK (input)
                 The dimension of the array WORK.  LDWORK  >=  max(1,N).   For
                 optimum  performance  LDWORK >= N*NB, where NB is the optimal
                 blocksize.

                 If LDWORK = -1, then a workspace query is assumed;  the  rou-
                 tine  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 LDWORK is issued by XERBLA.


       INFO (output)
                 = 0:  successful exit
                 < 0:  if INFO = -i, the i-th argument has an illegal value




                                  7 Nov 2015                        dorgqr(3P)