org.netlib.lapack
Class DLASQ4

java.lang.Object
  org.netlib.lapack.DLASQ4

public class DLASQ4
extends java.lang.Object

DLASQ4 is a simplified interface to the JLAPACK routine dlasq4.
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
 *  =======
 *
 *  DLASQ4 computes an approximation TAU to the smallest eigenvalue 
 *  using values of d from the previous transform.
 *
 *  I0    (input) INTEGER
 *        First index.
 *
 *  N0    (input) INTEGER
 *        Last index.
 *
 *  Z     (input) DOUBLE PRECISION array, dimension ( 4*N )
 *        Z holds the qd array.
 *
 *  PP    (input) INTEGER
 *        PP=0 for ping, PP=1 for pong.
 *
 *  NOIN  (input) INTEGER
 *        The value of N0 at start of EIGTEST.
 *
 *  DMIN  (input) DOUBLE PRECISION
 *        Minimum value of d.
 *
 *  DMIN1 (input) DOUBLE PRECISION
 *        Minimum value of d, excluding D( N0 ).
 *
 *  DMIN2 (input) DOUBLE PRECISION
 *        Minimum value of d, excluding D( N0 ) and D( N0-1 ).
 *
 *  DN    (input) DOUBLE PRECISION
 *        d(N)
 *
 *  DN1   (input) DOUBLE PRECISION
 *        d(N-1)
 *
 *  DN2   (input) DOUBLE PRECISION
 *        d(N-2)
 *
 *  TAU   (output) DOUBLE PRECISION
 *        This is the shift.
 *
 *  TTYPE (output) INTEGER
 *        Shift type.
 *
 *  Further Details
 *  ===============
 *  CNST1 = 9/16
 *
 *  =====================================================================
 *
 *     .. Parameters ..

Constructor Summary

DLASQ4()

Method Summary

static void

DLASQ4(int i0, int n0, double[] z, int pp, int n0in, double dmin, double dmin1, double dmin2, double dn, double dn1, double dn2, doubleW tau, intW ttype)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DLASQ4

public DLASQ4()

Method Detail

DLASQ4

public static void DLASQ4(int i0,
                          int n0,
                          double[] z,
                          int pp,
                          int n0in,
                          double dmin,
                          double dmin1,
                          double dmin2,
                          double dn,
                          double dn1,
                          double dn2,
                          doubleW tau,
                          intW ttype)