Provided by: liblapack-doc_3.3.1-1_all bug

NAME

       LAPACK-3  - 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

SYNOPSIS

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

           CHARACTER      COMPQ

           INTEGER        IFST, ILST, INFO, LDQ, LDT, N

           COMPLEX        Q( LDQ, * ), T( LDT, * )

PURPOSE

       CTREXC 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) CHARACTER*1
                = 'V':  update the matrix Q of Schur vectors;
                = 'N':  do not update Q.

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

        T       (input/output) COMPLEX array, dimension (LDT,N)
                On entry, the upper triangular matrix T.
                On exit, the reordered upper triangular matrix.

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

        Q       (input/output) COMPLEX array, dimension (LDQ,N)
                On entry, if COMPQ = 'V', the matrix Q of Schur vectors.
                On exit, if COMPQ = 'V', Q has been postmultiplied by the
                unitary transformation matrix Z which reorders T.
                If COMPQ = 'N', Q is not referenced.

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

        IFST    (input) INTEGER
                ILST    (input) INTEGER
                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.

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

 LAPACK routine (version 3.2)               April 2011                            CTREXC(3lapack)