title: Plot electric and magnetic field lines in a waveguide
body: <p>I was reading a pdf about electromagnetic propagation in different waveguides, and I was wondering how these kind of plots as shown in the picture can be visualized in MATLAB.</p>
  
  <p><img src="https://i.stack.imgur.com/fmYjy.png" alt="enter image description here"></p>
  
  <p>I have the solutions of <code>Ex</code>,<code>Ey</code>,<code>Hx</code> and <code>Hz</code> for a rectangular waveguide, and I am trying to plot the field lines for TE11 mode. I have tried to use <code>meshgrid</code> and <code>streamslice</code> but couldn't make it at all.</p>