ssvdct.f3

!>
!> SSVDCT counts the number NUM of eigenvalues of a 2*N by 2*N
!> tridiagonal matrix T which are less than or equal to SHIFT.  T is
!> formed by putting zeros on the diagonal and making the off-diagonals
!> equal to S(1), E(1), S(2), E(2), ... , E(N-1), S(N).  If SHIFT is
!> positive, NUM is equal to N plus the number of singular values of a
!> bidiagonal matrix B less than or equal to SHIFT.  Here B has diagonal
!> entries S(1), ..., S(N) and superdiagonal entries E(1), ... E(N-1).
!> If SHIFT is negative, NUM is equal to the number of singular values
!> of B greater than or equal to -SHIFT.
!>
!> See W. Kahan , Report CS41, Computer Science Dept., Stanford University,
!> July 21, 1966
!> 

N

!>          N is INTEGER
!>          The dimension of the bidiagonal matrix B.
!> 

S

!>          S is REAL array, dimension (N)
!>          The diagonal entries of the bidiagonal matrix B.
!> 

E

!>          E is REAL array of dimension (N-1)
!>          The superdiagonal entries of the bidiagonal matrix B.
!> 

SHIFT

!>          SHIFT is REAL
!>          The shift, used as described under Purpose.
!> 

NUM

!>          NUM is INTEGER
!>          The number of eigenvalues of T less than or equal to SHIFT.
!> 

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.