sorgtr (3p)

Name

sorgtr - generate a real orthogonal matrix Q which is defined as the product of n-1 elementary reflectors of order N, as returned by SSYTRD

Synopsis

SUBROUTINE SORGTR(UPLO, N, A, LDA, TAU, WORK, LWORK, INFO)

CHARACTER*1 UPLO
INTEGER N, LDA, LWORK, INFO
REAL A(LDA,*), TAU(*), WORK(*)

SUBROUTINE SORGTR_64(UPLO, N, A, LDA, TAU, WORK, LWORK, INFO)

CHARACTER*1 UPLO
INTEGER*8 N, LDA, LWORK, INFO
REAL A(LDA,*), TAU(*), WORK(*)




F95 INTERFACE
SUBROUTINE ORGTR(UPLO, N, A, LDA, TAU, WORK, LWORK, INFO)

CHARACTER(LEN=1) :: UPLO
INTEGER :: N, LDA, LWORK, INFO
REAL, DIMENSION(:) :: TAU, WORK
REAL, DIMENSION(:,:) :: A

SUBROUTINE ORGTR_64(UPLO, N, A, LDA, TAU, WORK, LWORK, INFO)

CHARACTER(LEN=1) :: UPLO
INTEGER(8) :: N, LDA, LWORK, INFO
REAL, DIMENSION(:) :: TAU, WORK
REAL, DIMENSION(:,:) :: A




C INTERFACE
#include <sunperf.h>

void sorgtr(char uplo, int n,  float  *a,  int  lda,  float  *tau,  int
*info);

void  sorgtr_64(char uplo, long n, float *a, long lda, float *tau, long
*info);

Description

Oracle Solaris Studio Performance Library                           sorgtr(3P)



NAME
       sorgtr  -  generate  a real orthogonal matrix Q which is defined as the
       product of n-1 elementary reflectors of order N, as returned by SSYTRD


SYNOPSIS
       SUBROUTINE SORGTR(UPLO, N, A, LDA, TAU, WORK, LWORK, INFO)

       CHARACTER*1 UPLO
       INTEGER N, LDA, LWORK, INFO
       REAL A(LDA,*), TAU(*), WORK(*)

       SUBROUTINE SORGTR_64(UPLO, N, A, LDA, TAU, WORK, LWORK, INFO)

       CHARACTER*1 UPLO
       INTEGER*8 N, LDA, LWORK, INFO
       REAL A(LDA,*), TAU(*), WORK(*)




   F95 INTERFACE
       SUBROUTINE ORGTR(UPLO, N, A, LDA, TAU, WORK, LWORK, INFO)

       CHARACTER(LEN=1) :: UPLO
       INTEGER :: N, LDA, LWORK, INFO
       REAL, DIMENSION(:) :: TAU, WORK
       REAL, DIMENSION(:,:) :: A

       SUBROUTINE ORGTR_64(UPLO, N, A, LDA, TAU, WORK, LWORK, INFO)

       CHARACTER(LEN=1) :: UPLO
       INTEGER(8) :: N, LDA, LWORK, INFO
       REAL, DIMENSION(:) :: TAU, WORK
       REAL, DIMENSION(:,:) :: A




   C INTERFACE
       #include <sunperf.h>

       void sorgtr(char uplo, int n,  float  *a,  int  lda,  float  *tau,  int
                 *info);

       void  sorgtr_64(char uplo, long n, float *a, long lda, float *tau, long
                 *info);



PURPOSE
       sorgtr generates a real orthogonal matrix Q which  is  defined  as  the
       product of n-1 elementary reflectors of order N, as returned by SSYTRD:

       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 triangle of  A  contains  elementary  reflectors
                 from  SSYTRD;  = 'L': Lower triangle of A contains elementary
                 reflectors from SSYTRD.


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


       A (input/output)
                 On entry, the vectors which define the elementary reflectors,
                 as returned by SSYTRD.  On exit, the N-by-N orthogonal matrix
                 Q.


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


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


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


       LWORK (input)
                 The  dimension  of  the array WORK. LWORK >= max(1,N-1).  For
                 optimum performance LWORK >= (N-1)*NB, where NB is the  opti-
                 mal 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




                                  7 Nov 2015                        sorgtr(3P)