title: Plotting multiple columns with ggplot2
body: <p>I need to plot the following dataset in the same graph.</p>
  
  <pre><code>Bin1,Bin2,Bin3,Cat
  4,3,5,S
  6,4,5,M
  3,5,4,M
  1,4,5,M
   ,5, ,M
  </code></pre>
  
  <p>In each bin, first data point belongs to a different category than the rest. (So I added the Cat column)</p>
  
  <p>I need to plot these as points (different colors for the different categories)</p>
  
  <p>Following lines of code achieve what I need for a single bin</p>
  
  <pre><code>p &lt;- ggplot(data,aes(Bin1,1))
  p + geom_point(aes(color=Cat, size=Cat))
  </code></pre>
  
  <p>How do I do this for the  entire dataset ?</p>
  
  <hr>
  
  <p>Here is a related question?</p>
  
  <p>What if I need to use a bunch of columns to color the points. Color Bin1 points according to Cat1 and so on..</p>
  
  <pre><code>Bin1,Cat1,Bin2,Cat2
  4,S,5,S
  6,L,5,M
  3,M,4,L
  1,M,5,L
      3,M
  </code></pre>
  
  <p>How do I do this??</p>