org.netlib.lapack
Class DLARFG

java.lang.Object
  org.netlib.lapack.DLARFG

public class DLARFG
extends java.lang.Object

DLARFG is a simplified interface to the JLAPACK routine dlarfg.
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
 *  =======
 *
 *  DLARFG generates a real elementary reflector H of order n, such
 *  that
 *
 *        H * ( alpha ) = ( beta ),   H' * H = I.
 *            (   x   )   (   0  )
 *
 *  where alpha and beta are scalars, and x is an (n-1)-element real
 *  vector. H is represented in the form
 *
 *        H = I - tau * ( 1 ) * ( 1 v' ) ,
 *                      ( v )
 *
 *  where tau is a real scalar and v is a real (n-1)-element
 *  vector.
 *
 *  If the elements of x are all zero, then tau = 0 and H is taken to be

 *  the unit matrix.
 *
 *  Otherwise  1 <= tau <= 2.
 *
 *  Arguments
 *  =========
 *
 *  N       (input) INTEGER
 *          The order of the elementary reflector.
 *
 *  ALPHA   (input/output) DOUBLE PRECISION
 *          On entry, the value alpha.
 *          On exit, it is overwritten with the value beta.
 *
 *  X       (input/output) DOUBLE PRECISION array, dimension
 *                         (1+(N-2)*abs(INCX))
 *          On entry, the vector x.
 *          On exit, it is overwritten with the vector v.
 *
 *  INCX    (input) INTEGER
 *          The increment between elements of X. INCX > 0.
 *
 *  TAU     (output) DOUBLE PRECISION
 *          The value tau.
 *
 *  =====================================================================
 *
 *     .. Parameters ..

Constructor Summary

DLARFG()

Method Summary

static void

DLARFG(int n, doubleW alpha, double[] x, int incx, doubleW tau)

Methods inherited from class java.lang.Object

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

Constructor Detail

DLARFG

public DLARFG()

Method Detail

DLARFG

public static void DLARFG(int n,
                          doubleW alpha,
                          double[] x,
                          int incx,
                          doubleW tau)