zungqr (3p)

Name

zungqr - N complex matrix Q with orthonormal columns, which is defined as the first N columns of a product of K elementary reflectors of order M

Synopsis

SUBROUTINE ZUNGQR(M, N, K, A, LDA, TAU, WORKIN, LWORKIN, INFO)

DOUBLE COMPLEX A(LDA,*), TAU(*), WORKIN(*)
INTEGER M, N, K, LDA, LWORKIN, INFO

SUBROUTINE ZUNGQR_64(M, N, K, A, LDA, TAU, WORKIN, LWORKIN, INFO)

DOUBLE COMPLEX A(LDA,*), TAU(*), WORKIN(*)
INTEGER*8 M, N, K, LDA, LWORKIN, INFO




F95 INTERFACE
SUBROUTINE UNGQR(M, N, K, A, LDA, TAU, WORKIN, LWORKIN,
INFO)

COMPLEX(8), DIMENSION(:) :: TAU, WORKIN
COMPLEX(8), DIMENSION(:,:) :: A
INTEGER :: M, N, K, LDA, LWORKIN, INFO

SUBROUTINE UNGQR_64(M, N, K, A, LDA, TAU, WORKIN, LWORKIN,
INFO)

COMPLEX(8), DIMENSION(:) :: TAU, WORKIN
COMPLEX(8), DIMENSION(:,:) :: A
INTEGER(8) :: M, N, K, LDA, LWORKIN, INFO




C INTERFACE
#include <sunperf.h>

void  zungqr(int m, int n, int k, doublecomplex *a, int lda, doublecom-
plex *tau, int *info);

void zungqr_64(long m, long n, long k, doublecomplex *a, long lda, dou-
blecomplex *tau, long *info);

Description

Oracle Solaris Studio Performance Library                           zungqr(3P)



NAME
       zungqr  - generate an M-by-N complex matrix Q with orthonormal columns,
       which is defined as the first N columns of a product  of  K  elementary
       reflectors of order M


SYNOPSIS
       SUBROUTINE ZUNGQR(M, N, K, A, LDA, TAU, WORKIN, LWORKIN, INFO)

       DOUBLE COMPLEX A(LDA,*), TAU(*), WORKIN(*)
       INTEGER M, N, K, LDA, LWORKIN, INFO

       SUBROUTINE ZUNGQR_64(M, N, K, A, LDA, TAU, WORKIN, LWORKIN, INFO)

       DOUBLE COMPLEX A(LDA,*), TAU(*), WORKIN(*)
       INTEGER*8 M, N, K, LDA, LWORKIN, INFO




   F95 INTERFACE
       SUBROUTINE UNGQR(M, N, K, A, LDA, TAU, WORKIN, LWORKIN,
              INFO)

       COMPLEX(8), DIMENSION(:) :: TAU, WORKIN
       COMPLEX(8), DIMENSION(:,:) :: A
       INTEGER :: M, N, K, LDA, LWORKIN, INFO

       SUBROUTINE UNGQR_64(M, N, K, A, LDA, TAU, WORKIN, LWORKIN,
              INFO)

       COMPLEX(8), DIMENSION(:) :: TAU, WORKIN
       COMPLEX(8), DIMENSION(:,:) :: A
       INTEGER(8) :: M, N, K, LDA, LWORKIN, INFO




   C INTERFACE
       #include <sunperf.h>

       void  zungqr(int m, int n, int k, doublecomplex *a, int lda, doublecom-
                 plex *tau, int *info);

       void zungqr_64(long m, long n, long k, doublecomplex *a, long lda, dou-
                 blecomplex *tau, long *info);



PURPOSE
       zungqr  generates  an M-by-N complex 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 ZGEQRF.


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 ZGEQRF 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 ZGEQRF.


       WORKIN (workspace)
                 On exit, if INFO = 0, WORKIN(1) returns the optimal  LWORKIN.


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

                 If  LWORKIN = -1, then a workspace query is assumed; the rou-
                 tine only calculates the optimal size of  the  WORKIN  array,
                 returns  this  value  as the first entry of the WORKIN array,
                 and no error message related to LWORKIN is issued by  XERBLA.


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




                                  7 Nov 2015                        zungqr(3P)