《DSP using MATLAB》示例Example4.5

x1 = [1, 2, 3]; x2 = [2, 4, 3, 5];                    % x1 x2 sequences
% n1 = 0:1:2; n2 = 0:1:3;
n1 = -1:1:1; n2 = -2:1:1;

[x3, n3] = conv_m(x1, n1, x2, n2);

figure(‘NumberTitle‘, ‘off‘, ‘Name‘, ‘Example4.5 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‘, ‘Example4.5 x3 sequence‘)
set(gcf,‘Color‘,‘white‘); 
stem(n3,x3); title(‘x3 sequence‘); xlabel(‘n‘); ylabel(‘x3(n)‘); grid on;