org.netlib.lapack
Class Dlasd8

java.lang.Object
  extended by org.netlib.lapack.Dlasd8

public class Dlasd8
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 * ======= * * DLASD8 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. * * DLASD8 is called from DLASD6. * * Arguments * ========= * * ICOMPQ (input) INTEGER * Specifies whether singular vectors are to be computed in * factored form in the calling routine: * = 0: Compute singular values only. * = 1: Compute singular vectors in factored form as well. * * 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 ) * On output, D contains the updated singular values. * * 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 DBEDE8. * 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 DBEDE8. * 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 ( LDDIFR, 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. * * LDDIFR (input) INTEGER * The leading dimension of DIFR, must be at least K. * * 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. * * WORK (workspace) DOUBLE PRECISION array, dimension at least 3 * K * * 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
Dlasd8()
           
 
Method Summary
static void dlasd8(int icompq, 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, int lddifr, 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

Dlasd8

public Dlasd8()
Method Detail

dlasd8

public static void dlasd8(int icompq,
                          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,
                          int lddifr,
                          double[] dsigma,
                          int _dsigma_offset,
                          double[] work,
                          int _work_offset,
                          intW info)