c3ex4.m

连续与离散信号系统的Matlab仿真示例代码．

%	Program to give partial Fourier sums of an 
%	odd square wave of unit amplitude
%
n_max = input('Enter vector of highest harmonic values desired (odd) ');
N = length(n_max);
t = 0:.002:1;
omega_0 = 2*pi;
for k = 1:N
	n = [];
	n = [1:2:n_max(k)];
	b_n = 4./(pi*n);		% Form vector of Fourier sine-coefficients
	x = b_n*sin(omega_0*n'*t);	% Rows of sine matrix are versus time; columns are versus n,
					% so matrix multiply sums over n
	subplot(N,1,k),plot(t, x), xlabel('t'), ylabel('partial sum'),...
	axis([0 1 -1.5 1.5]), text(.05,-.5, ['max. har. = ', num2str(n_max(k))])
end