slasq2(3F)

NAME
     SLASQ2 - SLASQ2 computes the singular values of a real N-by-N unreduced
     bidiagonal matrix with squared diagonal elements in Q and  squared off-
     diagonal elements in E

SYNOPSIS
     SUBROUTINE SLASQ2( M, Q, E, QQ, EE, EPS, TOL2, SMALL2, SUP, KEND, INFO )

         INTEGER        INFO, KEND, M

         REAL           EPS, SMALL2, SUP, TOL2

         REAL           E( * ), EE( * ), Q( * ), QQ( * )

PURPOSE
        SLASQ2 computes the singular values of a real N-by-N unreduced
        bidiagonal matrix with squared diagonal elements in Q and
        squared off-diagonal elements in E. The singular values are
        computed to relative accuracy TOL, barring over/underflow or
        denormalization.


ARGUMENTS
     M       (input) INTEGER
             The number of rows and columns in the matrix. M >= 0.

     Q       (output) REAL array, dimension (M)
             On normal exit, contains the squared singular values.

     E       (workspace) REAL array, dimension (M)

     QQ      (input/output) REAL array, dimension (M)
             On entry, QQ contains the squared diagonal elements of the
             bidiagonal matrix whose SVD is desired.  On exit, QQ is
             overwritten.

     EE      (input/output) REAL array, dimension (M)
             On entry, EE(1:N-1) contains the squared off-diagonal elements of
             the bidiagonal matrix whose SVD is desired.  On exit, EE is
             overwritten.

     EPS     (input) REAL
             Machine epsilon.

     TOL2    (input) REAL
             Desired relative accuracy of computed eigenvalues as defined in
             SLASQ1.

     SMALL2  (input) REAL
             A threshold value as defined in SLASQ1.
     SUP     (input/output) REAL
             Upper bound for the smallest eigenvalue.

     KEND    (input/output) INTEGER
             Index where minimum d occurs.

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