% GAUSSAB  nodes x (Legendre points) and weights w
%        for Gauss-Legendre quadrature for the interval [a,b]
%
% Adapted from Trefethen's gauss.m, Spectral Methods in MATLAB, SIAM, 2000

  function [x,w] = gaussab(N,a,b)
  beta = .5./sqrt(1-(2*(1:N-1)).^(-2));
  T = diag(beta,1) + diag(beta,-1);
  [V,D] = eig(T);
  x = diag(D); [x,i] = sort(x);
  w = 2*V(1,i).^2;

  x = a+(b-a)/2*(1+x);  % me
  w = ((b-a)/2)*w;      % me