title: Frequency spectrum of a square wave in MATLAB
body: <p>I need to plot the frequency spectrum for a square wave using MATLAB. The wave is HIGH (5mV) between 0 and -2 and LOW (omv) between 0 and 2. I have already obtained the fourier seires 
  for this function and i have the first ten components of the series.</p>
  
  <p>(5/2) + ((10/pi)*sin((pi*t)/2)) + ((10/(3*pi))*sin((3*pi*t)/2)) + ((10/(5*pi))*sin((5*pi*t)/2)) + ((10/(7*pi))*sin((7*pi*t)/2))+ ((10/(9*pi))*sin((9*pi*t)/2))+ ((10/(11*pi))*sin((11*pi*t)/2))+ ((10/(13*pi))*sin((13*pi*t)/2))+ ((10/(15*pi))*sin((15*pi*t)/2))+ ((10/(17*pi))*sin((17*pi*t)/2))+ ((10/(19*pi))*sin((19*pi*t)/2))</p>
  
  <p>How do I plot the frequency spectrum for this wave using MATLAB? I have tried using FFTs, but I really don't know how it works to plot the graph. </p>