org.netlib.lapack
Class DLASD5

java.lang.Object
  extended by org.netlib.lapack.DLASD5

public class DLASD5
extends java.lang.Object

DLASD5 is a simplified interface to the JLAPACK routine dlasd5.
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 * ======= * * This subroutine computes the square root of the I-th eigenvalue * of a positive symmetric rank-one modification of a 2-by-2 diagonal * matrix * * diag( D ) * diag( D ) + RHO * Z * transpose(Z) . * * The diagonal entries in the array D are assumed to satisfy * * 0 <= D(i) < D(j) for i < j . * * We also assume RHO > 0 and that the Euclidean norm of the vector * Z is one. * * Arguments * ========= * * I (input) INTEGER * The index of the eigenvalue to be computed. I = 1 or I = 2. * * D (input) DOUBLE PRECISION array, dimension ( 2 ) * The original eigenvalues. We assume 0 <= D(1) < D(2). * * Z (input) DOUBLE PRECISION array, dimension ( 2 ) * The components of the updating vector. * * DELTA (output) DOUBLE PRECISION array, dimension ( 2 ) * Contains (D(j) - lambda_I) in its j-th component. * The vector DELTA contains the information necessary * to construct the eigenvectors. * * RHO (input) DOUBLE PRECISION * The scalar in the symmetric updating formula. * * DSIGMA (output) DOUBLE PRECISION * The computed lambda_I, the I-th updated eigenvalue. * * WORK (workspace) DOUBLE PRECISION array, dimension ( 2 ) * WORK contains (D(j) + sigma_I) in its j-th component. * * Further Details * =============== * * Based on contributions by * Ren-Cang Li, Computer Science Division, University of California * at Berkeley, USA * * ===================================================================== * * .. Parameters ..


Constructor Summary
DLASD5()
           
 
Method Summary
static void DLASD5(int i, double[] d, double[] z, double[] delta, double rho, doubleW dsigma, double[] work)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

DLASD5

public DLASD5()
Method Detail

DLASD5

public static void DLASD5(int i,
                          double[] d,
                          double[] z,
                          double[] delta,
                          double rho,
                          doubleW dsigma,
                          double[] work)