title: Gnuplot - Using replot with png terminal
body: <p>I am trying to use replot with png terminal in Gnuplot.</p>
  
  <p>If I do the following I get two plots on one graph without any problem:</p>
  
  <pre><code>plot sin(x)/x
  replot sin(x)
  </code></pre>
  
  <p>Now if do the same for a png terminal type the resulting png file only contains the first plot.</p>
  
  <pre><code>set terminal png
  set output 'file.png'
  plot sin(x)/x
  replot sin(x)
  </code></pre>
  
  <p>Am I missing something at the end to get the second plot in my png file?</p>