Help to simsons rule

I need to solve the integral of exp(x) with the limits 1 to 2 The corect anwser is 4.67077

I wanna use this method, but I'm not sure how to change my own values over in the script.

figure, ezplot('sin(x)', [0, pi]), hold on
x = 0:.01:1;
plot(pi*x, 1 - 4*(x-.5).^2, 'r')
approx = zeros(1, 7); %initialize vector of results
for j = 1:7
    n = 2^j;
    x = pi*(0:1/n:1);
  weights = [1,2*ones(1,n-1)+2*mod([1:n-1],2),1] ;
    approx(j) = pi/(3*n)*sin(x)*weights';
end
disp('Using Simpson Rule')
disp('         n       Approximation')
for j = 1:7
    disp(['n = ', num2str(2^j, '%d'), '    ', num2str(approx(j), '%1.10f')])
end

I wanna use this method because it gives a n=2 4 8 16... and I have another script that can give me the error if I can just make this work. Please help me!