title: plot grouped data in R
body: <p>I have a grouped data as follows:</p>
  
  <pre><code>group   x   y
  group1  0   5
  group4  0   5
  group1  7   5
  group4  0   5
  group5  7   5
  group1  7   5
  group1  0   6
  group2  0   6
  group4  0   5
  group2  0   5
  group3  7   5
  </code></pre>
  
  <p>both x and y are discrete values having ranging between 0 and 7. I want to get a plot place each group data on the x-y plane according to their respective x and y values.For example, I can have multiple group1 points, all of which should share the same color. How to do that in R?</p>