Exponentially distributed eigenvalues
in (-0.5,-0.1]



Original matrix A of order 200
Find eigenvalues in interval (-0.50, -0.10]

(0)


Current subproblem after reduction to tridiagonal form
Reduce band back to tridiagonal whenever larger than 20

(1)


Current subproblem after iteration #1 (band = 7)
Theoretical bandgrowth shown in red

(2)


Current subproblem after iteration #2 (band = 26)
Theoretical bandgrowth shown in red

(3)


Current subproblem after band reduction
Reduce band back to tridiagonal whenever larger than 2

(4)


Current subproblem after iteration #3 (band = 7)
Theoretical bandgrowth shown in red

(5)


Current subproblem after iteration #4 (band = 21)
Theoretical bandgrowth shown in red

(6)


Current subproblem after band reduction
Reduce band back to tridiagonal whenever larger than 20

(7)


Current subproblem after iteration #5 (band = 3)
Theoretical bandgrowth shown in red

(8)


After 18 iterations, current subproblem has converged
Theoretical bandgrowth shown in red

(9)


Matrix A after divide #1 (subproblems of order 193 and 7)
Find eigenvalues in interval (-0.50, -0.10]

(10)


Matrix A after divide #2 (subproblems of order 176 and 17)
Find eigenvalues in interval (-0.50, -0.10]

(11)


Matrix A after divide #3 (subproblems of order 9 and 8)
Find eigenvalues in interval (-0.50, -0.10]

(12)


Matrix A after divide #4 (subproblem of order 8)
Subproblems smaller than 11 solved directly using LAPACK

(13)


Matrix A after divide #5 (subproblem of order 9)
Subproblems smaller than 11 solved directly using LAPACK

(14)


Eigenvalues of A (order N = 200)
There were 17 eigenvalue(s) found in (-0.50, -0.10]

(15)