% Example 2.11
%
% x(n) = u(n)-u(n-10)
% h(n) = (0.9)^n * u(n)
% diff eqn: y(n) - 0.9y(n-1) = x(n)
%
b = [1]; a = [1,-0.9];
n = -5:50; x = stepseq(0,-5,50) - stepseq(10,-5,50);
y = filter(b,a,x);
subplot(1,1,1);
subplot(2,1,2); stem(n,y); title('Output sequence')
xlabel('n'); ylabel('y(n)'); axis([-5,50,-0.5,8])