title: output.png from gnuplot is not as good as the figure from prompt shell
body: <p>I often plot graphs in <code>gnuplot</code> prompt shell, like this:</p>
  
  <pre><code>gunuplot&gt; plot sin(x) with linespoints pointtype 3
  </code></pre>
  
  <p>and the figure showed up is great.</p>
  
  <p>Today, I save the graph in a <code>.png</code> file, like this:</p>
  
  <pre><code>gnuplot&gt; set term png
  gnuplot&gt; set output "output.png"
  gunuplot&gt; plot sin(x) with linespoints pointtype 3
  </code></pre>
  
  <p>Then, I open <code>output.png</code> with <code>eog</code> in Ubuntu, like this:</p>
  
  <pre><code>$ eog output.png
  </code></pre>
  
  <p>I found that, the output.png displayed in <code>eog</code> is not as good as the figure plotted in prompt shell.</p>
  
  <p>Why is that? Do I need to adjust some settings before save the <code>output.png</code>?</p>
  
  <p><strong>PS</strong></p>
  
  <p>I found that a way around it, first, </p>
  
  <pre><code>set term postscript
  set output "output.ps"
  </code></pre>
  
  <p>then in linux shell,</p>
  
  <pre><code>$ convert output.ps output.jpg
  </code></pre>
  
  <p>This way some sort of solve the my problem.</p>