title: Gnuplot multiplot y-axis scaling
body: <p>I would like to be able to overlay a number of graphs using multiplot. I would like to enable auto-scaling to get the maximum resolution but I find that each dataset is independently scaled. Does anyone know how I might be able to scale all the graphs by the same amount so that they are all correct relative to each other ?</p>
  
  <p>My data is being supplied via a pipe from an external system but here is a simple example. If I plot these two signals I would like the plot scale to be +/- 2.0 (from the cos) and then the sin to be scaled appropriately so that it is only half the height of the cos, rather than both the same height.</p>
  
  <pre><code>set multiplot
  plot sin(x) with lines ls 1 linecolor rgb "blue"
  plot 2*cos(x) with lines ls 1 linecolor rgb "red"
  unset multiplot
  </code></pre>