ztrexc (3p)

Name

ztrexc - reorder the Schur factorization of a complex matrix A = Q*T*Q**H, so that the diagonal element of T with row index IFST is moved to row ILST

Synopsis

SUBROUTINE ZTREXC(COMPQ, N, T, LDT, Q, LDQ, IFST, ILST, INFO)

CHARACTER*1 COMPQ
DOUBLE COMPLEX T(LDT,*), Q(LDQ,*)
INTEGER N, LDT, LDQ, IFST, ILST, INFO

SUBROUTINE ZTREXC_64(COMPQ, N, T, LDT, Q, LDQ, IFST, ILST, INFO)

CHARACTER*1 COMPQ
DOUBLE COMPLEX T(LDT,*), Q(LDQ,*)
INTEGER*8 N, LDT, LDQ, IFST, ILST, INFO




F95 INTERFACE
SUBROUTINE TREXC(COMPQ, N, T, LDT, Q, LDQ, IFST, ILST, INFO)

CHARACTER(LEN=1) :: COMPQ
COMPLEX(8), DIMENSION(:,:) :: T, Q
INTEGER :: N, LDT, LDQ, IFST, ILST, INFO

SUBROUTINE TREXC_64(COMPQ, N, T, LDT, Q, LDQ, IFST, ILST, INFO)

CHARACTER(LEN=1) :: COMPQ
COMPLEX(8), DIMENSION(:,:) :: T, Q
INTEGER(8) :: N, LDT, LDQ, IFST, ILST, INFO




C INTERFACE
#include <sunperf.h>

void ztrexc(char compq, int n, doublecomplex *t, int ldt, doublecomplex
*q, int ldq, int ifst, int ilst, int *info);

void ztrexc_64(char compq, long n, doublecomplex *t, long ldt,  double-
complex *q, long ldq, long ifst, long ilst, long *info);

Description

Oracle Solaris Studio Performance Library                           ztrexc(3P)



NAME
       ztrexc  -  reorder  the  Schur  factorization  of  a complex matrix A =
       Q*T*Q**H, so that the diagonal element of T  with  row  index  IFST  is
       moved to row ILST


SYNOPSIS
       SUBROUTINE ZTREXC(COMPQ, N, T, LDT, Q, LDQ, IFST, ILST, INFO)

       CHARACTER*1 COMPQ
       DOUBLE COMPLEX T(LDT,*), Q(LDQ,*)
       INTEGER N, LDT, LDQ, IFST, ILST, INFO

       SUBROUTINE ZTREXC_64(COMPQ, N, T, LDT, Q, LDQ, IFST, ILST, INFO)

       CHARACTER*1 COMPQ
       DOUBLE COMPLEX T(LDT,*), Q(LDQ,*)
       INTEGER*8 N, LDT, LDQ, IFST, ILST, INFO




   F95 INTERFACE
       SUBROUTINE TREXC(COMPQ, N, T, LDT, Q, LDQ, IFST, ILST, INFO)

       CHARACTER(LEN=1) :: COMPQ
       COMPLEX(8), DIMENSION(:,:) :: T, Q
       INTEGER :: N, LDT, LDQ, IFST, ILST, INFO

       SUBROUTINE TREXC_64(COMPQ, N, T, LDT, Q, LDQ, IFST, ILST, INFO)

       CHARACTER(LEN=1) :: COMPQ
       COMPLEX(8), DIMENSION(:,:) :: T, Q
       INTEGER(8) :: N, LDT, LDQ, IFST, ILST, INFO




   C INTERFACE
       #include <sunperf.h>

       void ztrexc(char compq, int n, doublecomplex *t, int ldt, doublecomplex
                 *q, int ldq, int ifst, int ilst, int *info);

       void ztrexc_64(char compq, long n, doublecomplex *t, long ldt,  double-
                 complex *q, long ldq, long ifst, long ilst, long *info);



PURPOSE
       ztrexc  reorders  the  Schur  factorization  of  a  complex  matrix A =
       Q*T*Q**H, so that the diagonal element of T  with  row  index  IFST  is
       moved to row ILST.

       The  Schur  form  T is reordered by a unitary similarity transformation
       Z**H*T*Z, and optionally the matrix Q of Schur vectors  is  updated  by
       postmultplying it with Z.


ARGUMENTS
       COMPQ (input)
                 = 'V':  update the matrix Q of Schur vectors;
                 = 'N':  do not update Q.


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


       T (input/output)
                 On entry, the upper triangular matrix T.
                 On exit, the reordered upper triangular matrix.


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


       Q (input) On  entry, if COMPQ = 'V', the matrix Q of Schur vectors.  On
                 exit, if COMPQ = 'V', Q has been postmultiplied by  the  uni-
                 tary  transformation  matrix  Z which reorders T.  If COMPQ =
                 'N', Q is not referenced.


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


       IFST (input)
                 Specify the reordering of the diagonal  elements  of  T:  The
                 element  with  row  index  IFST  is  moved  to  row ILST by a
                 sequence of transpositions between adjacent elements.   1  <=
                 IFST <= N; 1 <= ILST <= N.


       ILST (input)
                 See the description of IFST.


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




                                  7 Nov 2015                        ztrexc(3P)