org.netlib.lapack
Class Dlasd9

java.lang.Object
  org.netlib.lapack.Dlasd9

public class Dlasd9
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
 *  =======
 *
 *  DLASD9 finds the square roots of the roots of the secular equation,
 *  as defined by the values in DSIGMA and Z.  It makes the
 *  appropriate calls to DLASD4, and stores, for each  element in D,
 *  the distance to its two nearest poles (elements in DSIGMA). It also
 *  updates the arrays VF and VL, the first and last components of all
 *  the right singular vectors of the original bidiagonal matrix.
 *
 *  DLASD9 is called from DLASD7.
 *
 *  Arguments
 *  =========
 *
 *  ICOMPQ  (input) INTEGER
 *          Specifies whether singular vectors are to be computed in
 *          factored form in the calling routine:
 *
 *             ICOMPQ = 0             Compute singular values only.
 *
 *             ICOMPQ = 1             Compute singular vector matrices in
 *                                    factored form also.
 *  K       (input) INTEGER
 *          The number of terms in the rational function to be solved by

 *          DLASD4.  K >= 1.
 *
 *  D       (output) DOUBLE PRECISION array, dimension(K)
 *          D(I) contains the updated singular values.
 *
 *  DSIGMA  (input) DOUBLE PRECISION array, dimension(K)
 *          The first K elements of this array contain the old roots
 *          of the deflated updating problem.  These are the poles
 *          of the secular equation.
 *
 *  Z       (input) DOUBLE PRECISION array, dimension (K)
 *          The first K elements of this array contain the components
 *          of the deflation-adjusted updating row vector.
 *
 *  VF      (input/output) DOUBLE PRECISION array, dimension(K)
 *          On entry, VF contains  information passed through SBEDE8.f
 *          On exit, VF contains the first K components of the first
 *          components of all right singular vectors of the bidiagonal
 *          matrix.
 *
 *  VL      (input/output) DOUBLE PRECISION array, dimension(K)
 *          On entry, VL contains  information passed through SBEDE8.f
 *          On exit, VL contains the first K components of the last
 *          components of all right singular vectors of the bidiagonal
 *          matrix.
 *
 *  DIFL    (output) DOUBLE PRECISION array, dimension (K).
 *          On exit, DIFL(I) = D(I) - DSIGMA(I).
 *
 *  DIFR    (output) DOUBLE PRECISION array,
 *                              dimension (LDU, 2) if ICOMPQ =1 and
 *                              dimension (K) if ICOMPQ = 0.
 *          On exit, DIFR(I, 1) = D(I) - DSIGMA(I+1), DIFR(K, 1) is not
 *          defined and will not be referenced.
 *
 *          If ICOMPQ = 1, DIFR(1:K, 2) is an array containing the
 *          normalizing factors for the right singular vector matrix.
 *
 *  WORK    (workspace) DOUBLE PRECISION array,
 *                                 dimension at least (3 * K)
 *          Workspace.
 *
 *  INFO    (output) INTEGER
 *          = 0:  successful exit.
 *          < 0:  if INFO = -i, the i-th argument had an illegal value.
 *          > 0:  if INFO = 1, an singular value did not converge
 *
 *  Further Details
 *  ===============
 *
 *  Based on contributions by
 *     Ming Gu and Huan Ren, Computer Science Division, University of
 *     California at Berkeley, USA
 *
 *  =====================================================================
 *
 *     .. Parameters ..

Constructor Summary

Dlasd9()

Method Summary

static void

dlasd9(int icompq, int ldu, int k, double[] d, int _d_offset, double[] z, int _z_offset, double[] vf, int _vf_offset, double[] vl, int _vl_offset, double[] difl, int _difl_offset, double[] difr, int _difr_offset, double[] dsigma, int _dsigma_offset, double[] work, int _work_offset, intW info)

Methods inherited from class java.lang.Object

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

Constructor Detail

Dlasd9

public Dlasd9()

Method Detail

dlasd9

public static void dlasd9(int icompq,
                          int ldu,
                          int k,
                          double[] d,
                          int _d_offset,
                          double[] z,
                          int _z_offset,
                          double[] vf,
                          int _vf_offset,
                          double[] vl,
                          int _vl_offset,
                          double[] difl,
                          int _difl_offset,
                          double[] difr,
                          int _difr_offset,
                          double[] dsigma,
                          int _dsigma_offset,
                          double[] work,
                          int _work_offset,
                          intW info)