%
%  CLENCURT nodes x (Chebychev points) and weights w for Clenshaw-Curtis quadrature
%

  function [x,w] = clencurt(N)

  theta = pi*(0:N)'/N;
  x = cos(theta);
  w = zeros(1,N+1); ii =2:N; v = ones(N-1,1);

  if mod(N,2)==0
    w(1) = 1/(N^2-1); w(N+1) = w(1);
    for k=1:N/2-1
      v = v-2*cos(2*k*theta(ii))/(4*k^2-1);
    end
    v = v - cos(N*theta(ii))/(N^2-1);
  else
    w(1) = 1/N^2; w(N+1) = w(1);
    for k=1:(N-1)/2
      v = v-2*cos(2*k*theta(ii))/(4*k^2-1);
    end
  end
  w(ii) = 2*v/N;