function y=sincplt(h,a,T,N)
%Spectrum of rectangular pulse train.
if rem(N,2)==0 N=N+1; end
n=1:N;
for i=1:N
   X(i)=(h*a/T)*sinc((i-floor(N/2)-1)*a/T);
end
subplot (2,1,1)
stem((n-floor(N/2)-1)/T,abs(X(n)))
xlabel('Frequency')
ylabel('Magnitude')
grid
subplot(2,1,2)
stem((n-floor(N/2)-1)/T,angle(X(n))/pi)
grid
xlabel('Frequency')
ylabel('Phase/pi')
disp('Fourier Coefficients')
disp(X)