matlab_trap

ns = 5 : 21;
n = length(ns);

y_theory = zeros(n, 1);
y_fact = zeros(n, 1);
y_runge = zeros(n, 1);
for i = 1 : n
    y_theory(i) = 0.4 / 12 * (0.4 / (ns(i) - 1))^2;
    y_fact(i) = abs(Trap(0, 0.4, ns(i)) + exp(-0.4) - 1);
    y_runge(i) = abs(Trap(0, 0.4, ns(i) * 2) - Trap(0, 0.4, ns(i))) / (2^2 - 1);
end;

semilogy(ns, y_theory, ns, y_fact, '--', ns, y_runge, '-.');
legend('теор.', 'факт.', 'Рунге');