org.netlib.lapack
Class Dlasq1

java.lang.Object
  extended by org.netlib.lapack.Dlasq1

public class Dlasq1
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 * ======= * * DLASQ1 computes the singular values of a real N-by-N bidiagonal * matrix with diagonal D and off-diagonal E. The singular values * are computed to high relative accuracy, in the absence of * denormalization, underflow and overflow. The algorithm was first * presented in * * "Accurate singular values and differential qd algorithms" by K. V. * Fernando and B. N. Parlett, Numer. Math., Vol-67, No. 2, pp. 191-230, * 1994, * * and the present implementation is described in "An implementation of * the dqds Algorithm (Positive Case)", LAPACK Working Note. * * Arguments * ========= * * N (input) INTEGER * The number of rows and columns in the matrix. N >= 0. * * D (input/output) DOUBLE PRECISION array, dimension (N) * On entry, D contains the diagonal elements of the * bidiagonal matrix whose SVD is desired. On normal exit, * D contains the singular values in decreasing order. * * E (input/output) DOUBLE PRECISION array, dimension (N) * On entry, elements E(1:N-1) contain the off-diagonal elements * of the bidiagonal matrix whose SVD is desired. * On exit, E is overwritten. * * WORK (workspace) DOUBLE PRECISION array, dimension (4*N) * * INFO (output) INTEGER * = 0: successful exit * < 0: if INFO = -i, the i-th argument had an illegal value * > 0: the algorithm failed * = 1, a split was marked by a positive value in E * = 2, current block of Z not diagonalized after 30*N * iterations (in inner while loop) * = 3, termination criterion of outer while loop not met * (program created more than N unreduced blocks) * * ===================================================================== * * .. Parameters ..


Constructor Summary
Dlasq1()
           
 
Method Summary
static void dlasq1(int n, double[] d, int _d_offset, double[] e, int _e_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

Dlasq1

public Dlasq1()
Method Detail

dlasq1

public static void dlasq1(int n,
                          double[] d,
                          int _d_offset,
                          double[] e,
                          int _e_offset,
                          double[] work,
                          int _work_offset,
                          intW info)