function [bp,wf]=crule(m) %usage: [bp,wf]=crule(m) % This function computes Gauss-Chebyshev base points and weight factors % using the algorithm given by somebody in 'SomeBook', % page 365, Academic Press, 1975, but modified by a change % in index variables: j=i+1 and m=n+1. % The weights are all wf_j=pi/m % and the base points are bp_j=cos((2j-1)*pi/2/m) % % m -- number of Gauss-Chebyshev points (integrates a (2m-1)th order % polynomial exactly) % % The Gauss-Chebyshev Quadrature integrates an integral of the form % 1 m % Int ((1/sqrt(1-z^2)) f(z)) dz = pi/m Sum (f(cos((2j-1)*pi/2/m))) % -1 j=1 % For compatability with the other Gauss Quadrature routines, I brought % the weight factor into the summation as % 1 m % Int ((1/sqrt(1-z^2)) f(z)) dz = Sum (pi/m * f(cos((2j-1)*pi/2/m))) % -1 j=1 % By Bryce Gardner, Purdue University, Spring 1993. j=[1:m]'; wf = ones(m,1) * pi / m; bp=cos( (2*j-1)*pi / (2*m) ); % end