dstect.f3

!>
!>    DSTECT counts the number NUM of eigenvalues of a tridiagonal
!>    matrix T which are less than or equal to SHIFT. T has
!>    diagonal entries A(1), ... , A(N), and offdiagonal entries
!>    B(1), ..., B(N-1).
!>    See W. Kahan , Report CS41, Computer Science Dept., Stanford
!>    University, July 21, 1966
!> 

N

!>          N is INTEGER
!>          The dimension of the tridiagonal matrix T.
!> 

A

!>          A is DOUBLE PRECISION array, dimension (N)
!>          The diagonal entries of the tridiagonal matrix T.
!> 

B

!>          B is DOUBLE PRECISION array, dimension (N-1)
!>          The offdiagonal entries of the tridiagonal matrix T.
!> 

SHIFT

!>          SHIFT is DOUBLE PRECISION
!>          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.