title: How to plot dots with different colors in gnuplot
body: <p>this is the first time that I use <code>gnuplot</code> . Therefore my question may be so obvious to solve but I could not figure it out. (I've already search on both stackoverflow and internet)</p>
  
  <p>Now I need to plot number of dots on the plot and my file is like that:</p>
  
  <p>dots-Xcoord dots-Ycoord  Color_of_dot</p>
  
  <pre><code>&gt; example:  
   1.1 0.234 "black"
   2.15 3.1 "black"
   1.76 0.94 "black"
   3.15 6.12 "blue"
   3.66 2.14 "blue"
  </code></pre>
  
  <p>So, to draw these dots on the graph I typed the following commands( non of them worked):</p>
  
  <pre><code>plot 'test.dat' using 1:2:3 with points pointtype 7 pointsize 1 lc variable
  
  plot 'test.dat' using 1:2:3 with points pointtype 7 pointsize 1 lc 3
  </code></pre>
  
  <p>However when I type the command like that: <code>plot 'test.dat' using 1:2 with points pointtype 7 pointsize 1 lc "black"</code> It works. So my question is that how could I assign color of a dot from a file? </p>