function squarewave(in)
clear all;clc;
i=1;
for t = -4:0.1:4
    y(i)=0.5;
    
    for n=1:2:3000       
        %y(i) = y(i)+ sin(n*t)/n;  
        y(i) =y(i)+sinc(n/2)*cos(2*pi*n*t/4);
    end        
        i=i+1;    
end

t = -4:0.1:4;
plot(t,y,'b');
%text(0.9,max(y),' \leftarrow Original Graph','FontSize',10)