The following MATLAB code plots a square wave.

I have attached the output. I am curious to know why MATLAB plots those vertical lines although I didn't ask it to.Code:x=linspace(-4*pi,4*pi,1000); for i=1:125 y(i)=1; end for i=125:250 y(i)=-1; end for i=250:375 y(i)=1; end for i=375:500 y(i)=-1; end for i=500:625 y(i)=1; end for i=625:750 y(i)=-1; end for i=750:875 y(i)=1; end for i=875:1000 y(i)=-1; end plot(x,y) axis([-4*pi 4*pi -2 2]) xlabel('x') ylabel('Square wave')