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NAME
     dlasq1 - DLASQ1 computes the singular values of  a  real  N-
     by-N bidiagonal  matrix with diagonal D and off-diagonal E

SYNOPSIS
     SUBROUTINE DLASQ1( N, D, E, WORK, INFO )

     INTEGER INFO, N

     DOUBLE PRECISION D( * ), E( * ), WORK( * )



     #include <sunperf.h>

     void dlasq1(int n, double *d, double *e, int *info) ;

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,    barring
     over/underflow or
        denormalization. The algorithm is described in

        "Accurate  singular  values  and  differential  qd  algo-
     rithms," by
        K. V. Fernando and B. N. Parlett,
        Numer. Math., Vol-67, No. 2, pp. 191-230,1994.

        See also
        "Implementation of differential qd algorithms," by
        K. V. Fernando and B. N. Parlett, Technical Report,
        Department of Mathematics, University  of  California  at
     Berkeley,
        1994 (Under preparation).


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
               (2*N)

     INFO      (output) INTEGER
               = 0:  successful exit
               < 0:  if INFO = -i, the i-th argument had an ille-
               gal value
               > 0:  if INFO = i, the algorithm did not converge;
               i  specifies  how many superdiagonals did not con-
               verge.

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