org.netlib.lapack
Class Dlasd5

java.lang.Object
  extended by org.netlib.lapack.Dlasd5

public class Dlasd5
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 * ======= * * 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, int _d_offset, double[] z, int _z_offset, double[] delta, int _delta_offset, double rho, doubleW dsigma, double[] work, int _work_offset)
           
 
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,
                          int _d_offset,
                          double[] z,
                          int _z_offset,
                          double[] delta,
                          int _delta_offset,
                          double rho,
                          doubleW dsigma,
                          double[] work,
                          int _work_offset)