function lambda = toeplitz_5s_eigenvalues ( row_num, col_num, alpha, beta, ... gamma ) %*****************************************************************************80 % %% TOEPLITZ_5S_EIGENVALUES returns the eigenvalues of the TOEPLITZ_5S matrix. % % Licensing: % % This code is distributed under the GNU LGPL license. % % Modified: % % 27 October 2007 % % Author: % % John Burkardt % % Reference: % % Robert Gregory, David Karney, % A Collection of Matrices for Testing Computational Algorithms, % Wiley, 1969, page 10, % LC: QA263.G68. % % Parameters: % % Input, integer ROW_NUM, the block order of A. % % Input, integer COL_NUM, the order of the subblocks of A. % % Input, real ALPHA, BETA, GAMMA the scalars that define A. % % Output, real LAMBDA(ROW_NUM*COL_NUM), the eigenvalues. % k = 0; for i = 1 : col_num angle_i = pi * i / ( col_num + 1 ); for j = 1 :row_num angle_j = pi * j / ( row_num + 1 ); k = k + 1 ; lambda(k) = alpha + 2.0 * beta * cos ( angle_i ) ... + 2.0 * gamma * cos ( angle_j ); end end return end