title: Multiple colors in the same line
body: <p>I would like to plot a sine curve in Matlab. But I want it blue for the positive values and red for the negative values.</p>
  
  <p>The following code just makes everything red...</p>
  
  <pre><code>x = [];
  y = [];
  for i = -180 : 180
      x = [x i];
      y = [y sin(i*pi/180)];
  end
  p = plot(x, y)
  set(p, 'Color', 'red')
  </code></pre>