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## org.netlib.lapack
Class Dlarra

    java.lang.Object
      org.netlib.lapack.Dlarra

    public class Dlarra

extends java.lang.Object

    Following is the description from the original
    Fortran source.  For each array argument, the Java
    version will include an integer offset parameter, so
    the arguments may not match the description exactly.
    Contact seymour@cs.utk.edu with any questions.

     *     ..
     *
     *  Purpose
     *  =======
     *
     *  Compute the splitting points with threshold SPLTOL.
     *  DLARRA sets any "small" off-diagonal elements to zero.
     *
     *  Arguments
     *  =========
     *
     *  N       (input) INTEGER
     *          The order of the matrix. N > 0.
     *
     *  D       (input) DOUBLE PRECISION array, dimension (N)
     *          On entry, the N diagonal elements of the tridiagonal
     *          matrix T.
     *
     *  E       (input/output) DOUBLE PRECISION array, dimension (N)
     *          On entry, the first (N-1) entries contain the subdiagonal
     *          elements of the tridiagonal matrix T; E(N) need not be set.
     *          On exit, the entries E( ISPLIT( I ) ), 1 <= I <= NSPLIT,
     *          are set to zero, the other entries of E are untouched.
     *
     *  E2      (input/output) DOUBLE PRECISION array, dimension (N)
     *          On entry, the first (N-1) entries contain the SQUARES of the

     *          subdiagonal elements of the tridiagonal matrix T;
     *          E2(N) need not be set.
     *          On exit, the entries E2( ISPLIT( I ) ),
     *          1 <= I <= NSPLIT, have been set to zero
     *
     *  SPLTOL (input) DOUBLE PRECISION
     *          The threshold for splitting. Two criteria can be used:
     *          SPLTOL<0 : criterion based on absolute off-diagonal value
     *          SPLTOL>0 : criterion that preserves relative accuracy
     *
     *  TNRM (input) DOUBLE PRECISION
     *          The norm of the matrix.
     *
     *  NSPLIT  (output) INTEGER
     *          The number of blocks T splits into. 1 <= NSPLIT <= N.
     *
     *  ISPLIT  (output) INTEGER array, dimension (N)
     *          The splitting points, at which T breaks up into blocks.
     *          The first block consists of rows/columns 1 to ISPLIT(1),
     *          the second of rows/columns ISPLIT(1)+1 through ISPLIT(2),
     *          etc., and the NSPLIT-th consists of rows/columns
     *          ISPLIT(NSPLIT-1)+1 through ISPLIT(NSPLIT)=N.
     *
     *
     *  INFO    (output) INTEGER
     *          = 0:  successful exit
     *
     *  Further Details
     *  ===============
     *
     *  Based on contributions by
     *     Beresford Parlett, University of California, Berkeley, USA
     *     Jim Demmel, University of California, Berkeley, USA
     *     Inderjit Dhillon, University of Texas, Austin, USA
     *     Osni Marques, LBNL/NERSC, USA
     *     Christof Voemel, University of California, Berkeley, USA
     *
     *  =====================================================================
     *
     *     .. Parameters ..

Constructor Summary
`Dlarra()`

Method Summary
`static void` | `dlarra(int n, double[] d, int _d_offset, double[] e, int _e_offset, double[] e2, int _e2_offset, double spltol, double tnrm, intW nsplit, int[] isplit, int _isplit_offset, intW info)`

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

Constructor Detail

### Dlarra

    public Dlarra()

Method Detail

### dlarra

    public static void dlarra(int n,
                              double[] d,
                              int _d_offset,
                              double[] e,
                              int _e_offset,
                              double[] e2,
                              int _e2_offset,
                              double spltol,
                              double tnrm,
                              intW nsplit,
                              int[] isplit,
                              int _isplit_offset,
                              intW info)

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