title: Octave plotting error
body: <p>I am new to octave, I just tried my first plotting with Octave 3.4.0 when I get the following error. Any help will be much appreciated. The gnuplot version is 4.6</p>
  
  <pre><code>     octave-3.4.0:3&gt; x=1:1:20;
       octave-3.4.0:4&gt; y=sin(x);
       octave-3.4.0:5&gt; plot(x,y)
  
       gnuplot&gt; set terminal aqua enhanced title "Figure 1" size 560 420  font "*,6"
                    ^
       line 0: unknown or ambiguous terminal type; type just 'set terminal' for a list
  </code></pre>
  
  <p>The terminal window I am using for octave is the mac X-terminal.</p>