代码：

x1 = [2, 3, 4]; x2 = [3, 4, 5, 6];            % x1 x2 sequences% n1 = 0:1:2; n2 = 0:1:3;n1 = 0:1:length(x1)-1; n2 = 0:1:length(x2)-1;[x3, n3] = conv_m(x1, n1, x2, n2);figure('NumberTitle', 'off', 'Name', 'Example4.4 x1 & x2 sequence')set(gcf,'Color','white'); subplot(2,1,1); stem(n1,x1); title('x1 sequence ');   xlabel('n'); ylabel('x1(n)'); grid on;subplot(2,1,2); stem(n2,x2); title('x2 sequence ');   xlabel('n'); ylabel('x2(n)'); grid on;figure('NumberTitle', 'off', 'Name', 'Example4.4 x3 sequence')set(gcf,'Color','white'); stem(n3,x3); title('x3 sequence'); xlabel('n'); ylabel('x3(n)'); grid on;

　　运行结果：