% fs1.m : FOURIER SERIES - PERIODIC RECTANGULAR PULSE SIGNAL
T  = 2;                % T = period
Tp = 1.5;              % Tp = width of pulse 
t = -T:0.005:T;        % t = time axis
wo = 2*pi/T;           % fundamental frequency
c0 = Tp/T;             % from the formula for c(k)
x = c0*ones(size(t));  % DC component of x(t)
figure(1)
clf
for k = 1:105
    figure(1)
   subplot(2,1,1)
   ck = Tp/T*sinc(k*wo*Tp/2/pi);    % the formula for c(k)
   xk = 2*ck*cos(k*wo*t);
   plot(t,xk);
   hold on
   x = x + xk;
   subplot(2,1,2)
   hold off
   plot(t,x)
   xlabel('t')
   title(['N = ',num2str(k)])
   pause(0.2)
end