% Chapter 3 : Example 3.21
%             Reconstruction using the stairs and plot functions
%
figure(1); clf
% Discrete-time Signal x1(n) : Ts = 0.0002
Ts = 0.0002; n = -25:1:25; nTs = n*Ts;
x = exp(-1000*abs(nTs));
% Analog Signal reconstruction using stairs
subplot(2,1,1); stairs(nTs*1000,x);
xlabel('t in msec.'); ylabel('xa(t)')
title('Reconstructed Signal from x1(n) using zero-order-hold'); hold on
stem(n*Ts*1000,x); hold off
%
% Analog Signal reconstruction using plot
subplot(2,1,2); plot(nTs*1000,x);
xlabel('t in msec.'); ylabel('xa(t)')
title('Reconstructed Signal from x1(n) using first-order-hold'); hold on
stem(n*Ts*1000,x); hold off