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## org.netlib.lapack
Class STREXC

    java.lang.Object
      org.netlib.lapack.STREXC

    public class STREXC

extends java.lang.Object

    STREXC is a simplified interface to the JLAPACK routine strexc.
    This interface converts Java-style 2D row-major arrays into
    the 1D column-major linearized arrays expected by the lower
    level JLAPACK routines.  Using this interface also allows you
    to omit offset and leading dimension arguments.  However, because
    of these conversions, these routines will be slower than the low
    level ones.  Following is the description from the original Fortran
    source.  Contact seymour@cs.utk.edu with any questions.

     *     ..
     *
     *  Purpose
     *  =======
     *
     *  STREXC reorders the real Schur factorization of a real matrix
     *  A = Q*T*Q**T, so that the diagonal block of T with row index IFST is

     *  moved to row ILST.
     *
     *  The real Schur form T is reordered by an orthogonal similarity
     *  transformation Z**T*T*Z, and optionally the matrix Q of Schur vectors
     *  is updated by postmultiplying it with Z.
     *
     *  T must be in Schur canonical form (as returned by SHSEQR), that is,
     *  block upper triangular with 1-by-1 and 2-by-2 diagonal blocks; each
     *  2-by-2 diagonal block has its diagonal elements equal and its
     *  off-diagonal elements of opposite sign.
     *
     *  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) REAL array, dimension (LDT,N)
     *          On entry, the upper quasi-triangular matrix T, in Schur
     *          Schur canonical form.
     *          On exit, the reordered upper quasi-triangular matrix, again
     *          in Schur canonical form.
     *
     *  LDT     (input) INTEGER
     *          The leading dimension of the array T. LDT >= max(1,N).
     *
     *  Q       (input/output) REAL 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
     *          orthogonal 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/output) INTEGER
     *  ILST    (input/output) INTEGER
     *          Specify the reordering of the diagonal blocks of T.
     *          The block with row index IFST is moved to row ILST, by a
     *          sequence of transpositions between adjacent blocks.
     *          On exit, if IFST pointed on entry to the second row of a
     *          2-by-2 block, it is changed to point to the first row; ILST
     *          always points to the first row of the block in its final
     *          position (which may differ from its input value by +1 or -1).
     *          1 <= IFST <= N; 1 <= ILST <= N.
     *
     *  WORK    (workspace) REAL array, dimension (N)
     *
     *  INFO    (output) INTEGER
     *          = 0:  successful exit
     *          < 0:  if INFO = -i, the i-th argument had an illegal value
     *          = 1:  two adjacent blocks were too close to swap (the problem
     *                is very ill-conditioned); T may have been partially
     *                reordered, and ILST points to the first row of the
     *                current position of the block being moved.
     *
     *  =====================================================================
     *
     *     .. Parameters ..

Constructor Summary
`STREXC()`

Method Summary
`static void` | `STREXC(java.lang.String compq, int n, float[][] t, float[][] q, intW ifst, intW ilst, float[] work, intW info)`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### STREXC

    public STREXC()

Method Detail

### STREXC

    public static void STREXC(java.lang.String compq,
                              int n,
                              float[][] t,
                              float[][] q,
                              intW ifst,
                              intW ilst,
                              float[] work,
                              intW info)

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