function [q, x, w] = integralglab (fun, a, b, n)
%
% function [q, x, w] = integralglab (fun, a, b, n)
%
% Formula di quadratura di Gauss-Legendre in [a,b] di ordine n..
xw = gauss (n + 1, r_jacobi (n + 1, 0, 0));
x = xw(:, 1) * (b - a) / 2 + (a + b) / 2;
w = xw(:, 2)' * (b - a) / 2;
q = w * fun (x);
