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
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);
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)