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 'Accurate Eigenvalues of a Symmetric Tridiagonal


 Matrix', 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.

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