cunghr (3p)

Name

cunghr - generate a complex unitary matrix Q which is defined as the product of IHI-ILO elementary reflectors of order N, as returned by CGEHRD

Synopsis

SUBROUTINE CUNGHR(N, ILO, IHI, A, LDA, TAU, WORK, LWORK, INFO)

COMPLEX A(LDA,*), TAU(*), WORK(*)
INTEGER N, ILO, IHI, LDA, LWORK, INFO

SUBROUTINE CUNGHR_64(N, ILO, IHI, A, LDA, TAU, WORK, LWORK, INFO)

COMPLEX A(LDA,*), TAU(*), WORK(*)
INTEGER*8 N, ILO, IHI, LDA, LWORK, INFO




F95 INTERFACE
SUBROUTINE UNGHR(N, ILO, IHI, A, LDA, TAU, WORK, LWORK, INFO)

COMPLEX, DIMENSION(:) :: TAU, WORK
COMPLEX, DIMENSION(:,:) :: A
INTEGER :: N, ILO, IHI, LDA, LWORK, INFO

SUBROUTINE UNGHR_64(N, ILO, IHI, A, LDA, TAU, WORK, LWORK,
INFO)

COMPLEX, DIMENSION(:) :: TAU, WORK
COMPLEX, DIMENSION(:,:) :: A
INTEGER(8) :: N, ILO, IHI, LDA, LWORK, INFO




C INTERFACE
#include <sunperf.h>

void cunghr(int n, int ilo, int ihi, complex *a, int lda, complex *tau,
int *info);

void cunghr_64(long n, long ilo, long ihi, complex *a, long  lda,  com-
plex *tau, long *info);

Description

Oracle Solaris Studio Performance Library                           cunghr(3P)



NAME
       cunghr  -  generate  a complex unitary matrix Q which is defined as the
       product of IHI-ILO elementary reflectors of order  N,  as  returned  by
       CGEHRD


SYNOPSIS
       SUBROUTINE CUNGHR(N, ILO, IHI, A, LDA, TAU, WORK, LWORK, INFO)

       COMPLEX A(LDA,*), TAU(*), WORK(*)
       INTEGER N, ILO, IHI, LDA, LWORK, INFO

       SUBROUTINE CUNGHR_64(N, ILO, IHI, A, LDA, TAU, WORK, LWORK, INFO)

       COMPLEX A(LDA,*), TAU(*), WORK(*)
       INTEGER*8 N, ILO, IHI, LDA, LWORK, INFO




   F95 INTERFACE
       SUBROUTINE UNGHR(N, ILO, IHI, A, LDA, TAU, WORK, LWORK, INFO)

       COMPLEX, DIMENSION(:) :: TAU, WORK
       COMPLEX, DIMENSION(:,:) :: A
       INTEGER :: N, ILO, IHI, LDA, LWORK, INFO

       SUBROUTINE UNGHR_64(N, ILO, IHI, A, LDA, TAU, WORK, LWORK,
              INFO)

       COMPLEX, DIMENSION(:) :: TAU, WORK
       COMPLEX, DIMENSION(:,:) :: A
       INTEGER(8) :: N, ILO, IHI, LDA, LWORK, INFO




   C INTERFACE
       #include <sunperf.h>

       void cunghr(int n, int ilo, int ihi, complex *a, int lda, complex *tau,
                 int *info);

       void cunghr_64(long n, long ilo, long ihi, complex *a, long  lda,  com-
                 plex *tau, long *info);



PURPOSE
       cunghr  generates  a  complex  unitary matrix Q which is defined as the
       product of IHI-ILO elementary reflectors of order  N,  as  returned  by
       CGEHRD:

       Q = H(ilo) H(ilo+1) . . . H(ihi-1).


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


       ILO (input)
                 ILO and IHI must have the same values as in the previous call
                 of CGEHRD. Q is equal to the unit matrix except in the subma-
                 trix Q(ilo+1:ihi,ilo+1:ihi).  1 <= ILO <= IHI <= N, if N > 0;
                 ILO=1 and IHI=0, if N=0.


       IHI (input)
                 See the description of IHI.


       A (input/output)
                 On entry, the vectors which define the elementary reflectors,
                 as returned by CGEHRD.  On exit, the N-by-N unitary 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 CGEHRD.


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


       LWORK (input)
                 The dimension of the array WORK. LWORK >= IHI-ILO.  For opti-
                 mum performance LWORK >= (IHI-ILO)*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                        cunghr(3P)