zungrq (3p)

Name

zungrq - N complex matrix Q with orthonormal rows, which is defined as the last M rows of a product of K elementary reflectors of order N

Synopsis

SUBROUTINE ZUNGRQ(M, N, K, A, LDA, TAU, WORK, LWORK, INFO)

DOUBLE COMPLEX A(LDA,*), TAU(*), WORK(*)
INTEGER M, N, K, LDA, LWORK, INFO

SUBROUTINE ZUNGRQ_64(M, N, K, A, LDA, TAU, WORK, LWORK, INFO)

DOUBLE COMPLEX A(LDA,*), TAU(*), WORK(*)
INTEGER*8 M, N, K, LDA, LWORK, INFO




F95 INTERFACE
SUBROUTINE UNGRQ(M, N, K, A, LDA, TAU, WORK, LWORK, INFO)

COMPLEX(8), DIMENSION(:) :: TAU, WORK
COMPLEX(8), DIMENSION(:,:) :: A
INTEGER :: M, N, K, LDA, LWORK, INFO

SUBROUTINE UNGRQ_64(M, N, K, A, LDA, TAU, WORK, LWORK,
INFO)

COMPLEX(8), DIMENSION(:) :: TAU, WORK
COMPLEX(8), DIMENSION(:,:) :: A
INTEGER(8) :: M, N, K, LDA, LWORK, INFO




C INTERFACE
#include <sunperf.h>

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

void zungrq_64(long m, long n, long k, doublecomplex *a, long lda, dou-
blecomplex *tau, long *info);

Description

Oracle Solaris Studio Performance Library                           zungrq(3P)



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


SYNOPSIS
       SUBROUTINE ZUNGRQ(M, N, K, A, LDA, TAU, WORK, LWORK, INFO)

       DOUBLE COMPLEX A(LDA,*), TAU(*), WORK(*)
       INTEGER M, N, K, LDA, LWORK, INFO

       SUBROUTINE ZUNGRQ_64(M, N, K, A, LDA, TAU, WORK, LWORK, INFO)

       DOUBLE COMPLEX A(LDA,*), TAU(*), WORK(*)
       INTEGER*8 M, N, K, LDA, LWORK, INFO




   F95 INTERFACE
       SUBROUTINE UNGRQ(M, N, K, A, LDA, TAU, WORK, LWORK, INFO)

       COMPLEX(8), DIMENSION(:) :: TAU, WORK
       COMPLEX(8), DIMENSION(:,:) :: A
       INTEGER :: M, N, K, LDA, LWORK, INFO

       SUBROUTINE UNGRQ_64(M, N, K, A, LDA, TAU, WORK, LWORK,
              INFO)

       COMPLEX(8), DIMENSION(:) :: TAU, WORK
       COMPLEX(8), DIMENSION(:,:) :: A
       INTEGER(8) :: M, N, K, LDA, LWORK, INFO




   C INTERFACE
       #include <sunperf.h>

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

       void zungrq_64(long m, long n, long k, doublecomplex *a, long lda, dou-
                 blecomplex *tau, long *info);



PURPOSE
       zungrq  generates  an  M-by-N  complex  matrix Q with orthonormal rows,
       which is defined as the last M  rows  of  a  product  of  K  elementary
       reflectors of order N

             Q  =  H(1)**H * H(2)**H . . . H(K)**H

       as returned by ZGERQF.


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


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


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


       A (input/output)
                 On entry, the (m-k+i)-th row must contain  the  vector  which
                 defines  the elementary reflector H(i), for i = 1,2,...,k, as
                 returned by ZGERQF in the last k rows of its  array  argument
                 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 ZGERQF.


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


       LWORK (input)
                 The dimension of the array  WORK.  LWORK  >=  max(1,M).   For
                 optimum  performance  LWORK  >= M*NB, where NB is the optimal
                 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 has an illegal value.




                                  7 Nov 2015                        zungrq(3P)