title: Pyplot: How to add mirrored second y-axis instead of negative values?
body: <p>In pyplot, how could I add a second y-axis where normally the negative values would be? The y-values should be increasing away from the shared x-axis.</p>
  <p>Above the x-axis I want to plot time consumption and below the x-axis space consumption. The x-axis is basically the current iteration.</p>