TESTING/EIG/dstect.f(3)    Library Functions Manual    TESTING/EIG/dstect.f(3)

NAME
       TESTING/EIG/dstect.f

SYNOPSIS
   Functions/Subroutines
       subroutine dstect (n, a, b, shift, num)
           DSTECT

Function/Subroutine Documentation
   subroutine dstect (integer n, double precision, dimension( * ) a, double
       precision, dimension( * ) b, double precision shift, integer num)
       DSTECT

       Purpose:


               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 'Accurate Eigenvalues of a Symmetric Tridiagonal
               Matrix', Report CS41, Computer Science Dept., Stanford
               University, July 21, 1966

       Parameters
           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.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 81 of file dstect.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0         TESTING/EIG/dstect.f(3)