Half sine wave fourier

% Program to give partial complex exponential Fourier sums of
% a half rectified sine wave of unit amplitude in table 2-1
clear
clc
k_max = input('Enter>>');
num_kmax = length(k_max);
for z = 1:num_kmax
    k = [-k_max(z):k_max(z)];
    L_k = length(k);
    a_k = zeros(1, L_k); % Form vector of Fourierseries coefficients,

    a_k((L_k+1)/2+1) = -0.25*j; % all odd-terms are zero except A(1)
    a_k((L_k+1)/2-1) = 0.25*j; % and A(-1) so define coefficient array

    for i=1:2:L_k % as a zero array and then
        a_k(i)=1/(pi*(1-k(i)^2)); % fill in nonzero values
    end;

    omega_0 = 2*pi;
    t = 0:.005:3;
    x = a_k*exp(j*omega_0*k'*t);

    subplot(num_kmax,1,z),plot(t,real(x)), ylabel('partialsum'),...
    axis([0 3 -0.5 1.2]), text(.05,-.25,['max. har. =',num2str(k_max(z))]),...
    text(2.0,-.25,['Name / Matric No']),
end;
xlabel('t');