org.netlib.lapack
Class DLASD0

java.lang.Object
  org.netlib.lapack.DLASD0

public class DLASD0
extends java.lang.Object

DLASD0 is a simplified interface to the JLAPACK routine dlasd0.
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
 *  =======
 *
 *  Using a divide and conquer approach, DLASD0 computes the singular
 *  value decomposition (SVD) of a real upper bidiagonal N-by-M
 *  matrix B with diagonal D and offdiagonal E, where M = N + SQRE.
 *  The algorithm computes orthogonal matrices U and VT such that
 *  B = U * S * VT. The singular values S are overwritten on D.
 *
 *  A related subroutine, DLASDA, computes only the singular values,
 *  and optionally, the singular vectors in compact form.
 *
 *  Arguments
 *  =========
 *
 *  N      (input) INTEGER
 *         On entry, the row dimension of the upper bidiagonal matrix.
 *         This is also the dimension of the main diagonal array D.
 *
 *  SQRE   (input) INTEGER
 *         Specifies the column dimension of the bidiagonal matrix.
 *         = 0: The bidiagonal matrix has column dimension M = N;
 *         = 1: The bidiagonal matrix has column dimension M = N+1;
 *
 *  D      (input/output) DOUBLE PRECISION array, dimension (N)
 *         On entry D contains the main diagonal of the bidiagonal
 *         matrix.
 *         On exit D, if INFO = 0, contains its singular values.
 *
 *  E      (input) DOUBLE PRECISION array, dimension (M-1)
 *         Contains the subdiagonal entries of the bidiagonal matrix.
 *         On exit, E has been destroyed.
 *
 *  U      (output) DOUBLE PRECISION array, dimension at least (LDQ, N)
 *         On exit, U contains the left singular vectors.
 *
 *  LDU    (input) INTEGER
 *         On entry, leading dimension of U.
 *
 *  VT     (output) DOUBLE PRECISION array, dimension at least (LDVT, M)

 *         On exit, VT' contains the right singular vectors.
 *
 *  LDVT   (input) INTEGER
 *         On entry, leading dimension of VT.
 *
 *  SMLSIZ (input) INTEGER
 *         On entry, maximum size of the subproblems at the
 *         bottom of the computation tree.
 *
 *  IWORK  INTEGER work array.
 *         Dimension must be at least (8 * N)
 *
 *  WORK   DOUBLE PRECISION work array.
 *         Dimension must be at least (3 * M**2 + 2 * M)
 *
 *  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
 *
 *  =====================================================================
 *
 *     .. Local Scalars ..

Constructor Summary

DLASD0()

Method Summary

static void

DLASD0(int n, int sqre, double[] d, double[] e, double[][] u, double[][] vt, int smlsiz, int[] iwork, double[] work, intW info)

Methods inherited from class java.lang.Object

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

Constructor Detail

DLASD0

public DLASD0()

Method Detail

DLASD0

public static void DLASD0(int n,
                          int sqre,
                          double[] d,
                          double[] e,
                          double[][] u,
                          double[][] vt,
                          int smlsiz,
                          int[] iwork,
                          double[] work,
                          intW info)