function x = lm_polynomial_zeros ( n, m ) %*****************************************************************************80 % %% LM_POLYNOMIAL_ZEROS returns the zeros for Lm(n,m,x). % % Licensing: % % This code is distributed under the GNU LGPL license. % % Modified: % % 09 March 2012 % % Author: % % Original FORTRAN77 version by Sylvan Elhay, Jaroslav Kautsky. % FORTRAN90 version by John Burkardt. % % Reference: % % Sylvan Elhay, Jaroslav Kautsky, % Algorithm 655: IQPACK, FORTRAN Subroutines for the Weights of % Interpolatory Quadrature, % ACM Transactions on Mathematical Software, % Volume 13, Number 4, December 1987, pages 399-415. % % Parameters: % % Input, integer N, the order. % % Input, integer M, the parameter. % 0 <= M. % % Output, real X(N), the zeros. % % % Define the zero-th moment. % zemu = r8_factorial ( m ); % % Define the Jacobi matrix. % bj = zeros ( n, 1 ); for i = 1 : n bj(i) = i * ( i + m ); end bj(1:n) = sqrt ( bj(1:n) ); x = zeros ( n, 1 ); for i = 1 : n x(i) = 2 * i - 1 + m; end w = zeros ( n, 1 ); w(1) = sqrt ( zemu ); % % Diagonalize the Jacobi matrix. % [ x, w ] = imtqlx ( n, x, bj, w ); return end